Results and Discussion



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Paper presented at the National Association of Research in Science Teaching Annual Meeting, Philadelphia, PA, March 25, 2003
Hands-On Science: The Impact of Haptic Experiences on

Attitudes and Concepts


M. Gail Jones1, Thomas Andre2, Atsuko Negishi1, Thomas Tretter1, Dennis Kubasko3,

Alexandra Bokinsky1, Russell Taylor1, Richard Superfine1


1 University of North Carolina at Chapel Hill

2Iowa State University

3University of North Carolina at Wilmington
Abstract

This study examined the impact of hands-on experiences for students exploring viruses using an Atomic Force Microscope. Through the use of a new tool known as a nanoManipulator students were able to manipulate and "feel" viruses. The 198 participants were divided into two treatment groups. Half the participants received full haptic (tactile) feedback while investigating viruses and half the participants were able to manipulate viruses under the microscope but did not receive tactile feedback. Analysis of the pre- and post-instruction assessments of knowledge and attitudes showed that all students improved in their knowledge of viruses. Those students who had the full haptic experience had better attitudes toward the investigations, and were more likely to make 3-dimensional models of viruses than those students who did not receive haptic feedback. The students with haptic feedback were also more knowledgeable about nanoscale objects and Atomic Force Microscopy.

For more than a decade science educators have advocated for students to have hands-on experiences in science classes (Shaw & Frederick, 1999; Sivertsen, 1993; Vesilind & Jones, 1996). There are “hands-on” science curricula, “hands-on” science museums, “hands-on” science clubs, and “hands-on” science books. A search of the Internet found more than 1.5 million references to hands-on science. At a fundamental level hands-on quite literally means “students ‘manipulate’ the things they are studying- plants, rocks, insects, water, magnetic fields—and ‘handle’ scientific instruments—rulers, balances, test tubes, thermometers, microscopes, telescopes, cameras, meters, calculators. In a more general sense, it seems to mean learning by experience” (Rutherford, 1993, p. 5).

Although hands-on science is often used in the broader sense to denote learning science by investigations and inquiry (Flick, 1993; Doran, 1990), the term has its roots in a belief that students must actively manipulate and handle materials and objects as part of their science explorations (Haury & Rillero, 1994; Lumpe & Oliver, 1991). “The concept of hands-on science is predicated on the belief that a science program… should be based on the method children instinctively employ to make sense of the world around them… These experiences should allow students to be actively engaged in the manipulation of everyday objects and materials from the real world” (Shapley & Luttrell, 1993, p. 1).

Science educators appear to hold firmly to a belief that this physical manipulation and handling of objects is an effective way for students to learn science (Vesilind & Jones, 1996). When students do hands-on science they are typically holding, touching, moving, observing, listening, smelling and sometimes tasting objects under investigation. This use of multiple senses in learning is often considered to be part of the developmental process of moving from concrete to abstract thinking (Loucks-Horsley et al., 1990). Piaget argued that hands-on or sensory-motor experiences are fundamental precursors to the subsequent development of formal operations (Wadsworth, 1989). In addition, Dewey promoted this notion of active engagement with materials accompanied by reflection (Dewey, 1916). Bruner also argued for active manipulations of materials, “the principal emphasis in education should be placed on skills - skills in handling, in seeing, and imaging, and in symbolic operations” (Bruner, 1983, p. 138).

Haptics


Although hands-on science is a widely accepted view of science teaching and learning, teachers and researchers have seldom questioned how and why it may be effective. What is it about touching and manipulating materials and objects that suggests a deeper, more effective type of knowing than that we obtain from sight or sound alone?

Teachers often refer to “grasping” concepts, or getting a “feel” for the experiment, or being “touched” by an observation or individual. Nobel prize winner Barbara McClintock talked about the importance of getting a “feel” for the subject of her research (Keller, 1983). These analogies suggest that at both the conscious and unconscious levels we recognize that there is a relationship between tactile perception and deeper levels of cognition.

Within the field of philosophy, Kant suggested the hand is man’s outer brain, arguing that touch is fundamental to our orientation in time and space (Tallis, 2001). Others have maintained that it is our use of the hand combined with the ability to use tools that makes us uniquely human. Tallis suggests that “(i)n the exploratory and manipulatory hand, prehension and comprehension are integrated, indeed fused” (2001, p. 25).

Perception, Cognition, and Touching. The underlying psychology of hands-on experiences provides clues as to the effectiveness of this teaching strategy. Hands-on manipulations are haptic experiences that involve exploratory and manipulative touch, in contrast to tactile sensations that result from external stimulation of skin receptors (Gibson, 1966; Kennedy, 1978). The term tactile is used primarily in referring to passive touch (being touched); the term haptic refers to active touch such as student manipulations during hands-on science explorations. The differences in tactile and haptic experiences are not trivial. Haptics involves both active touch and kinesthetics. Active touch involves intentional actions that an individual chooses to do, whereas passive touch can occur without any initiating action. In educational settings, involving students in consciously choosing to investigate the properties of an object is a powerful motivator and increases attention to learning (c.f., Sathian, 1998). Contrast this active manipulation with more passive types of learning, such as watching a science video. In active manipulation the student expends energy and makes a decision to manipulate materials. In more passive learning, such as watching a video, the student is involved primarily in observation. It is more difficult to maintain attention and motivation in a passive learning context than an active one. Associated with active manipulation is the opportunity for the student to control actions, learning, and even the speed of exploration (e.g., Lederman & Taylor, 1972). Control has been shown to be an important part of intrinsic motivation (Deci & Ryan, 1987; Deci et al., 1982).

Haptic perception involves sensors in the skin as well as the hand and arm. The movement that accompanies hands-on exploration involves different types of mechanoreceptors in the skin (involving deformation, thermoreception, and vibration of the skin), as well as receptors in the muscles, tendons, and joints involved in movement of the object (Verry, 1998). These different receptors contribute to a neural synthesis that interprets position, movement, and mechanical skin inputs. Druyan (1997) argues that this combination of kinesthetics and sensory perception creates particularly strong neural pathways in the brain.

For the science learner, kinesthetics allows the individual to explore concepts related to location, range, speed, acceleration, tension, and friction. Haptics enables the learner to identify hardness, density, size, outline, shape, texture, oiliness, wetness, and dampness (involving both temperature and pressure sensations) (Druyan, 1997; Schiffman, 1976).

When haptics is compared to vision in the perception of objects, vision typically is superior with a number of important exceptions. Visual perception is rapid and more wholistic—allowing the learner to take in a great deal of information at one time. Alternatively, haptics involves sensory exploration over time and space. If you give a student an object to observe and feel, the student can make much more rapid observations than if you only gave the student the object to feel without the benefit of sight. But of interest to science educators is the question of determining what a haptic experience adds to a visual experience. Researchers have shown that haptics is superior to vision in helping a learner detect properties of texture (roughness/ smoothness, hardness/ softness, wetness/ dryness, stickiness, and slipperiness) as well as microspatial properties of pattern, compliance, elasticity, viscosity, and temperature (Lederman, 1983; Zangaladze, et al., 1999). Vision dominates when the goal is the perception of macrogeometry (shape) but haptics is superior in the perception of microgeometry (texture) (Sathian et al., 1997; Verry, 1998). Haptics and vision together are superior to either alone for many learning contexts.


Haptic learning plays an important role in a number of different learning environments. Students with visual impairments depend on haptics for learning through the use of Braille as well as other strategies (Sathian, 2000). Technological advances now allow for haptics to be added to a variety of computer tools. Physicians use remote touch in minimally invasive surgery through the use of haptic interfaces with force sensors that allow the surgeon to “feel” tissues and organs during surgery (Lederman & Klatzky, 2001). Haptics has been added to virtual reality environments. A recent study found that participants were able to more efficiently learn virtual mazes when haptics were added than when there were no haptic feedback cues (Insko, et al., 2001). In the present study we explore a new instructional tool that adds haptics to microscopy. With this new haptics application, students are able to feel nanosized materials such as viruses that are imaged under an atomic force microscope (described further below). We examine how tactile and kinesthetic feedback influences students’ learning.
Research Questions

This study was designed to examine the impact of haptic and limited haptic experiences on students’ learning. Specifically we investigated the following questions:




  1. How do haptic experiences influence students’ concepts of viruses?

  2. Do haptic experiences with nano-sized objects change students’ understandings of nanoscale?

  3. Are there differences in attitudes for those students who have a full haptic experience compared to students who receive a limited haptic experience?

Methodology



Instrumentation. The nanoManipulator (nM) system allows students to control a probe to manipulate nanosized objects within an atomic force microscope (AFM). The atomic force microscope is part of a new generation of microscopes known as probing microscopes that use a very small 10-9m probe to manipulate and image objects such as viruses, nanotubes, and even molecules such as DNA. The nanoManipulator combines the atomic force microscope with software, a desktop computer, and a haptic joystick known as a Phantom. The Phantom is a 6-degree of freedom input and 3-degree of freedom output device, commercially available from Sensable Technologies (www.sensable.com). The Phantom allows the user to control a very sharp probe/tip with a radius of curvature of ~5-10 nm within the atomic force microscope to image surface topography at the nanometer scale. As the tiny tip attached to the end of a cantilever scans over the surface, a laser beam is bounced off the back of the cantilever on to a quadrant photodiode detector that monitors the vertical position of the tip on the surface while a piezoelectric crystal moves the tip with angstrom accuracy over the surface. The computer, which is keeping track of the tip-surface interaction, displays a real-time digital image of the scan. The AFM tip can be used like a finger to manipulate objects on the surface because the tip interacts physically with the surface. The forces used to manipulate nano-objects are in the range of pN to nN.

We used Microsoft Netmeeting software for video communication between the schools. The nanoManipulator software is available online (Public Domain Virtual Reality Peripheral Network library, www.cs.unc.edu/Research/vrpn). This software provides a real-time 3-dimensional image of the scanning surface. This image can be rotated and translated by the user such that the user can view the surface from all angles. Secondly, the robotic arm-like force feedback joystick, the Phantom, translates the tip movement and applies forces to the user’s hand corresponding to the forces applied to the tip within the microscope. The software is programmed so that the user can feel the surface as well as manipulate objects on the surface.

In this study students explore icosahedral-shaped adenoviruses. These viruses were selected because they are readily available (used in gene therapy research) and have a distinct shape. The study of viruses and other microbes and their role in causing disease is advocated in the Benchmarks for Science Literacy (American Association for the Advancement of Science, 1993) as well as the National Science Education Standards (National Research Council, 1996). The viruses are placed under the atomic force microscope at the university and the students are able to control the microscope tip through the Internet. They can see the results of their manipulations and feel the virus sample using the laptop and the Phantom joystick that are located at the school (from 4- 18 miles away from the university).

Participants. Eight science classes participated in the study. These included 4 classes of high school biology students and 4 classes of seventh graders enrolled in general science from two suburban school systems in the central region of North Carolina, including a total of 209 students (104 males, 105 females; 173 Euro-American, 30 African-American, and 6 of other ethnicities). Two different grade levels of science classes were used in order for us to explore whether or not the nanoManipulator is more effective with younger or older students.

Treatments. Half of the classes were randomly assigned to participate in instruction (described below) where the students were allowed to experience full haptic feedback from the nanoManipulator. This meant that the students could feel and experiment with viruses while receiving haptic feedback. They could feel the texture and shape of viruses that they could see on a computer screen. Furthermore, they could conduct investigations with viruses that involved pushing, poking, or rolling viruses to explore their properties.

The limited-haptic group (the control group) received the same instruction and had the same experiences except that the software program had been modified to cut off the haptic feedback from the nanoManipulator. Students could see the viruses and could use the joystick to control a visual probe during experimentation, but they did not receive tactile feedback. We view this as a limited- haptic experience because although students could not feel the viruses on the microscope, they still had hands-on experiences while making a paper model of a virus, making a paper tracing of a virus with a simulator (described below), and handling a plastic virus. We were unable to completely control for all haptic experiences because we wanted the instruction to be worthwhile for the participants and thus designed equivalent instructional experiences for the two treatment groups.


Instruction. Students received five days of instruction as part of this experience. On the first day, a scientist from the university came to the class and engaged students in a discussion designed to provide an overview of nanotechnology, viruses, and nanoscale. Instruction was also provided on scientific notation associated with small measures such as micrometer and nanometer, examples of objects typically measured at this scale, and information on how viruses replicate and attack cells.


On the second day, students rotated through three different stations, spending approximately 15 minutes at each station. One station was focused on training students how to use the nanoManipulator so that they would be prepared to use it for subsequent investigations. A second station had students explore scale concepts by having them compare their size to that of a toy dinosaur and compute various scale factors involved. The third station showed the short video Powers of 10 (http://www.powersof10.com). This video is organized around the principle of zooming in or out by a factor of 10 every 10 seconds, showing students what the universe would look like at various scales. This station gave students more practice at using scientific notation and strengthening their intuitive understanding of the scale associated with the notation.

The other three instructional days were spent by having students rotate through two additional stations a day, for a total of six stations in this segment. One of these stations had students build a paper icosahedral model of an adenovirus, insert a proportional length of yarn inside to simulate the virus’ DNA, and use a specially-constructed metal simulator to trace a tip over the virus and generate a two-dimensional slice of the virus’ shape on paper. This station was intended to help students understand how the atomic force microscope uses a scanning tip to probe the sample virus and generate an image for display on the computer. At a second station, students used the nanoManipulator (nM) to experiment with viruses. Depending on the treatment for a particular class, they either manipulated viruses with full haptic feedback or limited haptic feedback from the nM. Each student in the group manipulated at least one virus during their team’s time at the nM station and observed 3-4 other students’ investigations.

A third station was focused on teaching scale concepts. A clothesline with a 0 and 1 marked on it was strung across the room, and students were asked to place index cards with various powers of 10 in their approximately correct locations. After discussion with the group to correct any mistakes, students were then given pictures or words of various objects and told to clip them at approximately the correct location. A discussion was conducted comparing the various objects and determining how many of a given object would need to be lined up to be the same length as something else. A fourth station was reserved for students to write a newspaper article about their experiences. Suggestions were given as to what sorts of things they may write about, but students independently wrote their own stories. The fifth and sixth stations allowed students to interview nanoscience researchers from the university. Students were encouraged to ask the scientists questions about their work, their education, and their lives as scientists.

Assessments. Approximately two weeks prior to instruction, participants completed the pre-assessments (Knowledge Test, Beliefs Questionnaire, and the Pre-Opinion Questionnaire). One week after instruction, students completed post-assessment instruments (Post-Knowledge Test, Post-Experience Questionnaire, and the Post-Opinion Questionnaire). Students were interviewed individually approximately one to two weeks before and after the instruction. The assessments were designed to measure changes in knowledge as well as changes in beliefs and attitudes about the instructional experiences.

The Knowledge Test was developed by the researchers to assess students' fundamental knowledge of viruses, microscopy, and nanoscale. Students were asked to describe what they knew about viruses, to describe a nanometer and things that could be measured in nanometers, to identify and describe different types of microscopes, to describe an adenovirus, and to draw a picture of a virus.

The Beliefs and Opinion Questionnaire included items that asked students to rate their reactions to working with a microscope on a six point Likert scale that ranged from “very true of me” to “very untrue of me.” On the Post-Beliefs and Opinion Questionnaire students were asked to rate how much they had learned and how much the instructional experience had changed their views of learning.

The Experience Questionnaire included items that asked students to describe if and how the instructional experiences influenced how they felt about doing science. They were asked to describe additional experiments they would like to perform with the atomic force microscope.



Pre- and Post-Interviews contained items that asked about characteristics of the atomic force microscope and nanoManipulator, the characteristics of the adenovirus, how big viruses were, and about their perceptions of the learning experiences. These items were used to initiate the interactions with the students. The interviewers followed up on student responses to probe their understandings and reactions more deeply than could be done with written response assessments. At the end of each interview (pre- and post-) students were given a lump of clay and asked to make a model of a virus. After the construction task, they were asked to describe their virus model.

Analyses. Students responded on a 6-point Likert scale to each item on the beliefs and opinion questionnaire to indicate their degree of agreement or disagreement with each statement. These responses were first analyzed to investigate if students as a whole shifted in opinion from pretest to posttest. Then a proportional odds model was used to measure the differential impact of various factors such as haptics treatment, school level, and gender. This provides a Wald Chi-Square statistic to assess the significance of any differential shifting for each group.

Two researchers reviewed the student drawings and developed a coding scheme by grouping the characteristics of viruses that students depicted. Each drawing was classified on dimensionality – whether or not the drawing indicated a significant sense of depth to the virus or if it was primarily 2-dimensional. Each drawing was also classified according to its shape including: viral shapes such as icosahedral (the adenovirus) or bacteriophages, non-viral shapes such as an amoeba-shape, paramecium, cell, or irregular shapes not classifiable into any of the other categories. The two researchers then individually coded a class set of drawings, compared classifications, and after discussion of any differences, independently coded another class set. The interrater reliability was 88% agreement. One of the researchers continued coding the rest of the drawings.

During the individual interviews pre- and post-experience, students were given a piece of modeling clay and asked to make a virus. The clay model coding scheme was accomplished similarly to the drawings. If students used the clay as if it were paint and created a flat image of a virus the clay model was coded as 2-dimensional. Using the same categories developed for the drawings, two researchers independently coded a class set for both dimensionality and shape, discussed any differences, and then coded a second class set. The interrater reliability was 91% agreement and one of the researchers coded the rest of the clay models.

The drawings and the clay models from the pretest and posttest were analyzed for shifts in design from 2-dimensional to 3-dimensional and for a shift in non-viral shapes to viral shapes for all students. A proportional odds model was used to measure the differential impact of various factors such as haptics treatment, school level, and gender. This model provides a Wald Chi-Square statistic to assess the significance of any differential shifting by group.

In both the interviews and the written assessments given pre- and post-instruction, students were asked to list objects that would normally be measured in nanometers. Responses were coded as correct (e.g. viruses, DNA, atoms, molecules), incorrect (e.g. dust, bugs, sand) or mixed if they included items in both categories. Results were analyzed with logistic regression to determine if all groups of students improved in ability to name nanosized objects, and were also analyzed to determine if different groupings of students improved to different degrees.

Results

There were significant gains in attitudes and knowledge of viruses from pre- to post-instruction for students in all eight classes. The instruction was novel and interesting to most students and the majority of students developed more positive attitudes toward microscope investigations and gained knowledge about virus morphology and nanoscale. There were differences in the full haptic and limited-haptic treatment groups. These results are described in the sections that follow.




Student Attitudes and Beliefs


Students were asked to respond to four questions regarding their attitudes towards engaging in science activities (see Table 1). Their attitudes were indicated on a 6-point Likert scale both pretest and posttest. A logistic regression proportional odds model showed a statistically significant shift in attitudes for the full-haptic and modified-haptic groups, from pretest frequencies to posttest frequencies in three of the four questions (see Table 1), with the strongest shift occurring in response to how interesting students would find using a microscope to investigate a scientific problem. The strong reversal of opinion by students on the question of interest level attests to the impact of the experience in changing student attitudes about microscope investigations.
Table 1

Student attitudes towards engaging in science activities


Question 1 2 3 4 5 6 Mean

Very true Very untrue

of me of me

____________________________________________________________________________________________________________

I would find using a microscope to investigate a PRE 9 19 50 29 54 28 3.97

scientific problem frustrating.*** POST 6 4 17 29 56 75 4.87
I would find using a microscope to investigate a PRE 8 10 20 40 65 46 4.49

scientific problem interesting.*** POST 61 72 24 10 14 6 2.26


I would find using a microscope to investigate a PRE 13 8 30 38 54 46 4.32

scientific problem boring.*** POST 4 9 17 28 56 73 4.83


I believe that doing science for a living would be PRE 28 18 39 36 37 31 3.68

a boring life. POST 24 16 29 36 42 39 3.93

____________________________________________________________________________________________________________

Note. The values represent frequencies of student responses in each category pretest and posttest. The last column is the weighted mean.

***p<.001 for the Wald Chi-Square in logistic model analysis of effects.

A proportional odds model was run for each of these four items to assess the impact of various factors on the model: prebeliefs (scores on the pretest); haptics (full haptic feedback vs. limited haptic feedback); school (middle school students vs. high school students); and gender (female or male). Table 2 below shows the logistic regression model for each of the four items and the haptic treatment.

Table 2

Pproportional odds model analysis of attitudes

Question

I would find using a microscope to investigate a scientific problem frustrating.
I would find using a microscope to investigate a scientific problem interesting.
I would find using a microscope to investigate a scientific problem boring.
I believe that doing science for a living would be a boring life.

Odds ratio


Haptics

1.867 *

--

2.196 **



--



Note. The entries represent the odds ratio for the proportional odds model for those factors with p-values less than .05. The dashes indicate a nonsignificant (at the .05 level) p-value. Prebeliefs was significant for all but the first question. Neither school nor gender were significant for any item.

* p<.05

** p<.01

Neither the school level nor the gender of the students had a statistically significant relationship with their attitudes as measured by these four items. Not surprisingly, students’ prebeliefs had an impact on many of the questions. However, Table 2 shows that the availability of full haptic feedback during the experience had a significant impact for responses to half of the items. For the “frustrating” question, the odds of those with limited haptic feedback being in a lower category (less favorable) on the posttest is nearly twice the odds for those with full haptic feedback. For the “boring” question, the odds of those with limited haptic feedback being in a lower category (less favorable) on the posttest is more than twice the odds for those with full haptic feedback. The addition of haptic feedback to the atomic force microscope experience seems to have made the experience less frustrating and less boring for the students.

A factor analysis shows that the four items listed in tables 1 and 2 are can be reduced to one factor both pretest and posttest (see Table 3), and so can reasonably be combined into an aggregate attitude score.

Table 3

Principal Components Analysis of four individual attitude items


Question (Items from Tables 1 and 2)

… frustrating.

… interesting.

… boring.

would be a boring life.

Pre Post


.743 .624

.803 .835

.846 .852

.730 .730




Note. Entries represent linear weighting coefficients for creating one component from the four individual items.

Because the weighting coefficients are similar in magnitude to each other, a composite attitude score for each student was created by equally weighting each of these four items and summing the result. Using the Wald Chi-Square in a logistic regression model analysis of effects, the posttest composite attitude score showed a significant (p<.0001) effect of composite pre-attitude scores and a significant (p<.01) positive effect of having full haptic feedback (odds ratio = 2.175). These results indicate that students’ composite attitude was positively impacted by the presence of full haptic feedback during the experimentation.

Student beliefs about the process of science were also evaluated using a Likert scale (see Table 4). There were significant changes from pre- to post-instruction on students’ beliefs about science involving memorizing things and getting the right answer and beliefs that scientists mainly do research on problems in which they must create or generate answers that cannot be known in advance. Students also shifted in their belief of the practice of science as being a collaborative team effort as opposed to being done by individuals in isolation.



Table 4

Student Beliefs About Science


1 2 3 4 5 6

Question Very true Very untrue Mean

of me of me


I believe that doing science involves mostly PRE 17 15 37 35 48 36 4.01

memorizing things and getting the right answer.*** POST 8 11 18 28 60 60 4.63
I believe that scientists mainly do research on PRE 13 24 30 52 43 25 3.87

problems in which they must create or generate POST 32 30 53 33 25 12 3.14

answers that cannot be known in advance.***
I believe that real science consists of teams of PRE 6 3 6 28 64 82 5.05

women and men working together to carry out POST 83 60 21 10 3 9 2.02

experiments in order to solve problems or

understand better how things work.***



Note. The values represent frequencies of student responses in each category pretest and posttest. The last column is the weighted mean.

*** p<.0001 for the Wald Chi-Square in logistic regression model analysis of effects.



Student Conceptions of Viruses


The study of virus characteristics and morphology is a typical part of middle and high school science curricula and textbooks (cf. Raven & Johnson, 1999; Johnson, 1998). This study gave students a chance to interact with actual viruses as opposed to studying them from a textbook or other written source. As a result of these experiences, students’ conceptions of viral shapes underwent a significant shift (see Table 5).

Table 5

Virus shapes


Representation mode Virus shape Other shape

Drawing*** PRE 21 144

POST 118 47
Clay model*** PRE 30 134

POST 125 39

Note. The values represent frequencies of students who represented a virus shape (icosahedral like the adenovirus or phage-like) or some other shape.

***p<.0001 for the Wald Chi-Square in a logistic regression model analysis of effects.

Students’ representations of viruses via a drawing and via creating a clay model showed similar shifts in thinking. The majority of students began the experience with a conception of a virus that was not correct, most often visualizing a shape similar to an amoeba, a cell, a paramecium, or else an amorphous shape without any specific characteristics. After the experiences investigating viruses, the majority shifted their thinking to hold a scientific conception of a viral shape, either icosahedral like the adenovirus they experimented with, or else a phage-like shape (see Figure 1). The ability to investigate and manipulate actual viruses seemed to help solidify a previously vague notion of what a virus looks like.

In order to assess the impact of the haptic experience, we coded the dimensionality of students’ representations of viruses for the drawings and the clay models (2-dimensional, or 3-dimensional viruses). Table 6 shows that the mode of representation, drawing or clay model, seemed to impact the dimensionality of students’ representations.

Table 6

Virus dimensionality


Representation mode 2-D 3-D

Drawing*** PRE 153 12

POST 83 82
Clay model*** PRE 85 81

POST 27 139

Note. The values represent frequencies of student responses.

***p<.0001 for the Wald Chi-Square in logistic regression model analysis of effects.

More clay models were 3-dimensional than were the drawings both pretest and posttest. It is likely that the clay models lend themselves to thinking 3-dimensionally more easily than a 2-dimensional sheet of paper for drawing. However, in both representational modes, there was a significant shift from 2-dimensional to 3-dimensional representations. Instruction involving the ability to interact with and feel actual viruses may contribute to such a shift in thinking as compared to instruction using a more traditional 2-dimensional textbook representation of a virus.


Students’ Knowledge of Nanoscale


Students were asked to list objects that would normally be measured in nanometers. Responses were counted correct if they were able to name at least one object that is nanosized, even if they also named others that typically wouldn’t be measured in nanometers, such as cells which are generally too large to typically use nanometers as the preferred unit of measurement. Table 7 summarizes student responses.

Table 7

Knowledge of nanometer scale objects


correcta incorrecta

Pretest 71 116

Posttest 178 9

Note. The values represent the frequencies of student responses.

aA response was counted correct if it was at least partially correct, and incorrect otherwise.

p<.0001 for the Wald Chi-Square in logistic regression model analysis of effects.

A number of students initially thought of objects such as sand, dirt, or bugs as small enough to comfortably be measured in nanometers because such objects are normally thought of as “small” from our macroscopic viewpoint. However, after this experience most students had a better sense of how small a nanometer is as shown by nearly all of them being able to name at least one object typically measured with that unit.

Several other items support the finding that students improved their understanding of nanoscale as a result of this experience. A question on the posttest asked students to select from among five multiple choice responses how many times they would be shrunk to reach the size of a virus. Of the 187 students, 32% chose the correct response on the posttest, which is significantly higher (, df=1, p<.0001) than the 20% that might be expected if in fact the responses were randomly chosen from the five choices. Students were also asked on the posttest to order four objects (human cell, virus, bacterium, atom) from largest to smallest. Responses were coded for correctness of the virus being listed as smaller relative to both the human cell and bacterium. 80% of the students correctly indicated this position for the size of a virus, suggesting a good conception of a virus’ size relative to some other typical microscopic objects encountered in the curriculum.


Discussion


The instruction resulted in students in both the limited-haptics and the full haptics conditions developing more positive attitudes about science, working with microscopes, and doing science for a living. The instructional experiences were highly novel involving new tools and areas of study (nanoscale science, viruses, and microscopy) and regardless of the treatment, students were highly engaged and interested in the topics. Students in both groups showed significant gains in understanding viruses (particularly virus morphology and diversity of types). Students in both treatment groups moved from holding a 2-dimensional concept of viruses to a 3-dimensional concept. One explanation for this is that most students learn about viruses from textbooks and the media, with most images coming from 2-dimensional print media. The majority of the students in this study had limited knowledge of the shapes of viruses and the high quality 3-dimensional graphics and the construction of the paper virus model may have been sufficient to promote a shift toward 3-dimensional concepts. The clay modeling assessment was more sensitive than the drawings in measuring the 2-dimensional to 3-dimensional concepts. This supports the need for researchers and teachers to use a variety of assessment tasks (beyond paper and pencil) to detect changes in learning.

Students in both treatment groups made significant gains in their understandings of nanometer scale. Although scale is considered to be a major theme that runs across the disciplines of science, the students in this study appeared to have very little understanding of what a nanometer is or the magnitudes of differences that exist between the size of a virus and the size of a human. Students often reported that viruses were larger than bacteria and that human cells were as small or smaller than a virus. Overall if something was microscopic it tended to be grouped by the students as “small” with little differentiation between micrometer-sized objects and those that are nanometer-sized. Given the recent explosion of nanotechnology developments and the need for an informed populous to participate in decision-making related to the nanotechnology industry, the lack of understanding of nanoscale may prove to be problematic.

Those students who experienced the full haptic feedback had significantly better attitudes than those students who were in the limited-haptic treatment group. Science teachers have argued that hands-on experiences are more interesting to students, and these data suggest that there may be reasons for the supposed benefits of hands-on science experimentation. The full haptic treatment students received tactile feedback that provided more sensory experiences than the limited-haptic treatment group. It is possible that the additional novel sensory information the haptic joystick provided made the experience more interesting to students. The haptic experiences the students had with viruses involved a type of active touch that allowed students to control and choose their manipulations, as well as to receive more specific tactile feedback.

Future Research


Lederman and Taylor (1972) have suggested that the unique aspects of the “touching system” as used in the haptic treatment allows individuals a significant measure of control over their active touching. This intentional and active process accompanied by increased sensations may create what Druyan (1997) describes as particularly strong neural pathways in the brain. All of the students in the two treatments could see the viruses they were investigating, both groups of students used kinesthetics to explore the viruses, but only the full-haptic group received tactile feedback. Further brain research is needed to determine if Druyan is correct and the combinations of vision, touch, and kinesthetics provide more durable and perhaps develop more connected neural pathways.

Haptics are particularly suited to enable individuals to perceive microspatial geometric properties such as elasticity, compliance, or viscosity and other attributes such as roughness, wetness, and stickiness. It is possible that haptics affords learners additional sensory information about these types of properties related to viruses but our assessments were not able to capture changes in these perceptual properties from pre- to post-instruction. We are currently designing a new study to measure how texture may influence a learner’s concept of an unknown object.

It is possible that the haptic experiences we provided in this instruction may differentially affect students with different cognitive abilities. We speculate that for learning disabled students with reading or writing disabilities, haptic experiences may be particularly beneficial by providing multisensory experiences. Recent work by Grant, Zangaladze, Thiagarajah, & Sathian (1999) in the area of neuropsychology has reported that students with dyslexia tend to have deficits on well-defined tactile tasks. It is possible that the left-right orientation of the probing microscope (AFM) and the left-right movement of the Phantom joystick could exacerbate existing directional problems that a dyslexic may have. For these students, the haptic microscopy experiences may be more confusing than learning through a class lecture or examining 2-dimensional print materials. For students with visual impairments hapic experiences may be very well suited. Blind students typically use a variety of different haptic learning devices to assist their perceptual learning. Further research is needed to assess the effectiveness of the nanoManipulator with students with visual and spatial disabilities.

Summary and Conclusions


The assessments showed that across treatment groups there were significant gains from pre- to post-instruction. Students had better attitudes toward microscope investigations and engaging in science activities. Students’ beliefs about science moved away from a view of science as having a “right” answer and more toward a view of science as a process in which teams of women and men work together to solve problems or understand better how things work. From a cognitive perspective, students in both treatment groups developed conceptual models of viruses that were more consistent with current scientific research. They were more likely to move from a 2-dimensional to a 3-dimensional understanding of virus morphology. There were significant changes in students’ understandings of scale; after instruction students were more likely to identify examples of nano-sized objects and be able to describe the degree to which a human would have to be shrunk to reach the size of a virus. Students who were able to both feel and manipulate the viruses were significantly more likely to state that using a microscope to investigate a scientific problem was not frustrating and more students in the full haptic treatment disagreed that using a microscope to investigate a scientific problem was boring.

This finding that haptic experiences had a significant impact on students’ attitudes may be due to the increased sensory feedback and stimulation that may have made the experience more engaging and motivating to students. The feedback also provided students with additional information about the texture and shape of the viruses that they were investigating. This additional information may have made the experience more novel and interesting. Further work is needed to see if the impact of haptics on attitudes toward learning persists across content domains and types of experimentation. In addition, further research can document whether haptic experiences differ from visual experiences in the way concepts are formed and the nature of the conceptualization.

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Notes

This material is based upon work supported by the National Science Foundation under Grant No. 0087389.


Appreciation is extended to Chris Wiesen, Odum Institute for Research in Social Science for advice on the statistical analysis.

Figure 1


Pre-Instruction Clay Models of Viruses


Post-Instruction Clay Models of Viruses








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