School Science Lessons
2024-02-27a
1. Science, Maths and Technology, Scientific Literacy
(topic01)
Table of contents
2.0 Why are hands-on science activities so effective for student learning?
2.1 What makes an activity scientific?
2.2 Experimental investigations
2.3 Report on an experimental investigation
2.4 Science, Maths and Technology
2.5 Biology experiments, artificial and concomitant variation
2.6 Biology experiments, use of live animals
2.0 Why are hands-on science activities so effective for student learning?
by Dr Donna Satterthwait, School of Education, University of Tasmania, Australia
Teaching Science, Volume 56, Number 2, June 2010, pp. 7-10
About the author: Dr Satterthwait has been a science teacher educator since 1991 and has a passion for "spreading the word" of science as a way of making sense of the natural world.
From effective research, there is a general consensus that hands-on experiences help students to learn.
The question that this paper seeks to answer is what it is all about these activities that fosters student learning.
In a review of the literature, three factors have been identified as making a significant contribution to this strategy's success.
They are peer interaction through co-operative learning, object-mediated learning, and embodied experience.
By taking these factors into account, teachers of science can design lessons that explicitly utilize this knowledge.
Introductionbr>
The experiential value of hands-on activities in science education has long been recognized as significant in engaging students.
Hands-on activities represent a strategy of teaching in which the students usually work in groups, interact with peers to manipulate various objects, ask questions that focus observations, collect data and attempt to> explain natural phenomena.
This is actually the essence of science.
Bredderman reported on the effectiveness of three of the then "new" primary science programs developed in the United States, all of which were activity-based and showed considerable benefits to participating students, because of their emphasis on the use of hands-on strategies.
In a review of further research on the hands-on learning pedagogy, such activities have been shown to improve children's science learning and achievement and their attitudes towards science, increase science skill proficiency and language development, (specifically reading and oral communication), and also to encourage creativity.
The potential for learning through hands-on activities is quite amazing.
Despite each having a different emphasis, seven innovative primary science curriculum projects funded and sponsored by the National Science Foundation, American Association for the Advancement of Science, or the US Office of Education and various large universities (e.g. Harvard, University of California), all had the use
of hands-on science activities as an essential component of their project design.
However, not only do these funding organizations, educational researchers, curriculum project leaders and designers know that hands-on activities promote better student learning outcomes, but from their own classroom experiences, most teachers of science agree.
These teachers incorporate and promote a "hands-on, minds-on" approach in their practice, because they believe their students benefit from the implementation of this strategy.
This style of teaching is also well supported by evidence in other subject areas.
The pedagogy of using hands-on investigations, Involving students working in groups, and manipulating objects has been recognized as a desired science teaching strategy for almost 200 years, and continues to influence science education curriculum design as seen in the more recently developed Australian Academy of Science-sponsored Primary Connections modules.
Thus, a question needs to be asked - why is the teaching of science through the provision of classroom hands-on science activities so efficacious?
It is time to consider this pedagogic practice in light of new research on learning and to link this teaching strategy with some of the theoretical understandings that have emerged, especially from the domain of cognitive psychology.
This literature review may help to generate discussions and hypotheses that can be investigated in science classrooms.
Understanding of Learning
The processes of learning are highly complex.
To make meaning of these processes, cognitive psychologists categorize what data and evidence they have collected into various "explanatory models" that provide a convenient way of communicating multifaceted ideas and serve to integrate concepts and research findings into systems that generate hypotheses and future applications.
In this way, the cognitive psychologists' knowledge of human learning can be advanced and better understood.
However, the considerable progress that has been made in understanding how learning takes place is rarely incorporated into classroom practice in a deliberate way, but teachers "know" what usually works in their own classrooms, they can predict likely outcomes of their students' engagement with particular tasks.
Good, experienced teachers have a deep understanding of their students' needs and attempt to address them as best they can to achieve intended outcomes.
One reason for the disjunct between knowledge about learning among cognitive psychologists and teachers' understanding of their students' learning is that there are many different cognitive models and psychological explanations of how learning occurs in individuals, and most have validity for particular instances that are often narrowly defined and contextual.
What happens in the reality of the classroom is so much messier than the variable-controlled investigations of psychologists.
Straightforward explanations are difficult to apply to messy classroom contexts.
The gap that occurs between the psychologist's experimental knowledge and the teacher's classroom nous is widened by the teacher's difficulty in comprehending the vocabulary of the psychologist, as well as the psychologist's lock of understanding of classroom situations.
Some psychologists may have a naive view of classroom culture, because of their long held expectations of how a classroom should operate.
Stereotypical classroom cultural expectations, which rarely reflect reality, also prevail throughout our society.
This gap between teachers and psychological knowledge becomes especially obvious in neurological or brain-based deficit studies, although recently there has been a deliberate attempt to bridge the divide, as more is being discovered about brain function.
Some neuroscientists are looking at ways in which their "models" can inform classroom learning.
The human brain appears to be highly interconnected and, like a classroom, complex and multidimensional.
Neuroscientific studies provide enticing evidence of plasticity in cellular interactions, establishment of networks and integration of neurones and neurochemicals.
Doidge gives examples of how different sections of the brain interact and function together and influence thinking, finding that imagining doing and actually doing both excite the same parts of the brain, imagining one is using one's muscles actually strengthens them.
As even more knowledge about brain function becomes available, new models about learning are likely to be proposed.
The development of these new "brain learning" models, when added to previously proposed cognitive models of learning, make the time right to re-examine cognition models and classroom practices to gain more insight and attempt to better understand why particular teaching strategies "work".
A good place to start this process is to call attention to one such pedagogy, the "hands-on activity", a well-regarded science teaching strategy and examine why this strategy seems to cause students to learn.
Although there may be many attributes that contribute to the apparent success of student learning within this way of teaching, for the purpose of this paper three factors have been identified that play a significant role in the hands-on practice.
The three factors presented in this paper are:
1. The influence of co-operative learning and social constructivist understandings,
2. Mediated learning through the use of objects, and
3. Embodiment as a way of students gaining understanding and making meaning of their experiences.
Hands-on Experience Student Learning outcomes
Peer object-mediated embodied interaction learning experience
The question becomes how each factor contributes to the whole - that is, the students' learning of science.
In this paper, these three factors will be defined and then discussed in light of recent literature from research studies in cognitive psychology.
1. Peer Interaction Through Co-operative Learning
Social constructivism theory informs the teacher of the importance of co-operative group work for learning to occur among students.
Effective understanding is closely associated with co-operative learning pedagogy.
As stated by Hattie, ". . . co-operative learning has a prime effect on enhancing interest and problem solving, provided it is set up with high levels of peer involvement.
The sharing of knowledge, observations and beliefs among peers through dialogue is at the core of social constructivism".
As a translator of theory into classroom practice, Lemke, advocates that students be given an opportunity to engage in "side conversations", especially those that describe, compare or discuss real objects or events using the scientific terms in a flexible way appropriate to the situation.
Shifts in understanding need group discussions and / or arguments to enhance the creation of new meaning, so the provision of peer interactions in the classroom seems to be an especially important prerequisite for establishing thought-provoking conversations.
Numerous studies and reviews have been undertaken and published that demonstrate the key conceptual principle that humans make meaning of their encounters through the comparison of the current with the previous, that humans need to make sense of what they experience, and that they share knowledge by exchanging information through interactions with each other, usually in dialogue.
Notions of prior understanding and the discrepant event have greatly influenced how science lessons and units are planned and implemented.
Social constructivism theory informs the teacher that if an individual student's ideas are to be changed, new experiences that challenge prior knowledge need to be provided.
The teacher of science provides opportunities to challenge pseudoscientific beliefs through hands-on group work; research has demonstrated that the creation of cognitive dissonance can promote considerable knowledge transformation, to address and challenge misunderstandings.
2. Object-mediated Learning
Some of the most productive, and common, science activities are those that involve the manipulation of objects.
This factor plays a significant role in motivating and focussing our students on the learning of science through the use of objects in an activity in which they are to be engaged.
Lev Vygotsky, the educationalist often identified with social constructivism, viewed tools ("technical tools" in terms of objects, or "psychological tools" as symbols or signs), as defining and shaping human activity, not merely facilitating it.
Similarly, object-mediated learning contributes to students' learning by causing them to question or seek explanations of the effects of an object's use in particular on texts to bring about results, which at times are surprising.
It seems as if the objects themselves possess attributes that by their very nature implicitly "instruct" their usage.
What is it about the object that contributes to how it is used and what is learnt through its usage?
Children have been observed to alternate between playing with objects and learning from objects, alternating between "What can I do with this object,
and "What does this object do?"
Manipulations of three-dimensional things deliver an event reality that is in itself intriguing and triggers curiosity among the students.
It is this physical connection to the object and the characteristics of the object that allow manipulation, and thus learning, to occur.
Often, during lab activities, students "play" with equipment in ways that are testing the object's design, construction or purpose!
As well, students are more likely to remember things that elicit a positive emotional response.
Students enjoy laboratory activities, they enjoy manipulating equipment and observing the changes they cause.
Students of chemistry ranked interest in chemistry classroom investigations over demonstrations, films, discussion or lectures, and students had even more positive attitudes towards chemistry when they participated in genuine inquiry activities, rather than more traditional "recipe" practicals.
2. Embodiment
The third factor, embodiment, is closely linked to object-mediated learning since object manipulation requires movement of the human body.
Embodied learning can be defined as how we humans make sense of our perceptions and actions as we negotiate our journey through our surroundings.
By being present, interacting with others and using equipment, an experience is created and understood through this physicality.
For example, recent data indicate that the brain is modified by the use of tools: . . . that the use of tools can change the pattern of movement, because the body schema has changed.
This comment was based on a study that provided direct evidence that using tools changes the way in which the brain detects our body parts.
The mind and the body are not separate entities, as had been thought by many philosophers, most famously, Descartes.
Rather the mind and body work synergistically to build a repository of understandings expressed in brain structure and abstract ideas.
The structure and function of the body are represented within the neural networks of the brain, and the formation of these networks is a prerequisite to being able to remember and imagine experiences.
From our varied experiences, our ability to create and imagine develops and grows as the neural network in our brain develops.
Strick, Dum and Fiez, discuss neurological data that show how the cerebral cortex, the part of the brain that has long been associated with thinking processes, links with the cerebellum, the recognized area of motor regulation.
They conclude that, ". . . the cerebellum plays a functionally important role in human cognition and affect".
It appears that the brain's anatomy and function are interconnected to all human endeavours, including learning, thinking and moving.
Perception has been shown to be intimately linked to culture.
Nisbeft and Masuda, showed that cognitive differences exist in how East Asians and Westerners.
Additionally, this is expressed in commonly used phrases that influence how we conceptualize ideas.
Language usage is indicative of the close association between understanding, experiences and brain development.
How humans move is how humans learn is how humans experience.
Implications for the science classroom
How then can we as teachers of science incorporate these research findings into our classroom practice to enhance our students' learning experiences?
Listed below are a few possible ideas that can readily be implemented with science hands-on activities.
These suggestions are not necessarily new to the practise of science teaching, but they are those practices that have been shown to enhance learning:
1. Find out what students know before the lesson sequence begins, especially to identify any misunderstandings they might have and then attempt to address these through co-operative learning group science activities.
2. Foster conversations among the students that involve asking and responding to good, thought-provoking questions, set up situations where the students can play the devil's advocate.
As well, you could write a different question on a slip of paper for each science activity group.
The group discusses it and then presents their response to the class.
Other students would then be invited to agree or disagree with the response.
3. Require students to manipulate objects in usual and unusual ways and to collect this information as part of their investigation.
Perhaps include the students' ideas on how the equipment should be arranged and used, and let them try their own ideas rather than giving them a predetermined diagram or procedure.
4. Attempt to include lessons in which exploration is promoted.
When safe and appropriate, encourage students to "play" with the materials to help them identify properties (or limitations), of the objects for themselves.
Think of other ways in which we could see (or imagine), what would happen if the objects were used differently.
Summary
All three of these factors, co-operative learning, object manipulation and embodiment, contribute to the underlying efficacy of hands-on activities in science education.
New ideas about how neural networks interact and integrate the totality of human experiences in the gaining of knowledge call for teachers to plan for the learning experience as a whole, rather than as smaller parts.
Teachers of science have evolved a powerful teaching strategy, the hands-on activity, that characterizes this more holistic model of learning.
Typical hands-on activities incorporate dialogue through co-operative group work, the manipulation of objects and the collection of embodied sensory inputs in conjunction with the neurobiology and aesthetics of the mind, all of which create opportunities for students to make meaning of the natural world.
Further analysis of hands-on science group work may result in a better understanding of how teachers can sustain engagement and learning among our students.
Science educators should recognize their contribution towards enhanced teaming through the implementation of the hands-on strategy.
Becoming explicitly aware of factors that characterize hands-on teaching and their potential to cause student learning, teachers of science can make explicit decisions that enhance and strengthen such learning opportunities.
These factors, along with teachers' observations of students' actions in information collection and processing, allow teachers of science to make meaning of their pedagogy and to design even more productive learning activities within which our students can engage in science.
2.1 What makes an activity scientific?
Based on UNESCO source book for science in the primary school by Wynne Harlen and Jos Elst-geest "A checklist for reviewing activities".
First, carry out this activity, which involves making a parachute.
It is presented as it appeared on a worksheet for children.
Parachute lesson
1. Cut a 35-cm square from sturdy plastic.
2. Cut four pieces of string 35-cm long.
3. Securely tape or tie a string to each corner of the plastic.
4. Tie the free ends of the four strings together in a knot.
Be sure the strings are all the same length.
5. Tie a single string about 15-cm long the knot.
6. Add a weight, e.g. a metal washer, to the free end of the string.
7. Pull the parachute up in the centre.
Squeeze the plastic to make it as flat as possible.
8. Fold the parachute twice.
9. Wrap the string loosely around the plastic.
10. Throw the parachute up into the air or from a veranda or drop it from a height
Results - The parachute opens and slowly carries the weight to the ground.
Why? - The weight falls first, unwinding the string, because the parachute, being larger, is held back by the air.
The air fills the plastic, slowing down the rate of descent.
If the weight falls too quickly a lighter object must be used.
Now apply the items of the check list to what you did.
How many items did you tick?
The exact number will depend to some extent on the context in which rig, but it is probably four or five from items 1 to 12 and none the list.
Why is the activity in opportunities for learning?
It could be the starting point for discussing gravity, balanced and unbalanced forces, speed and acceleration, air resistance and the properties of different materials.
How can the activity be modified to make it a potentially greater learning experience?
Here is a suggestion.
It starts in the same way as before.
Thereafter the questions and suggestions might be introduced orally by the teacher rather than on a worksheet.
Parachute lesson, Steps 1. to 10.
What happens?
Does everyone's parachute do the same?
What is the same about the way all the parachutes fall?
What is different?
Why do you think that is?
If you throw up a weight not attached to a parachute, does it fall as quickly as the one attached to the parachute?
Try it.
Discuss with others in your group why this might be.
Do you think that if the parachute is bigger, or smaller, it will make a difference?
Decide how you will compare how quickly different parachutes fall.
Keep a record of how quickly the different sizes fall.
2.2 Experimental investigations
Investigation: "The process of examining or inquiring into something with organization, care and precision." Queensland Studies Authority.
Summary.
Hypothesis-based inquiry
Inquiry process
Define the question.
Gather information and resources.
Form hypothesis.
Do experiment and collect data.
Analyse data.
Interpret data and draw conclusions that serve as a starting point for new hypotheses.
Publish / present results.
Set down the topic being investigated and the objectives for studying the topic.
Establish and refine the hypothesis as a statement or question.
Gather and analyse data relevant to the hypothesis.
Synthesize and evaluate data relevant to the hypothesis.
Confirm or reject the hypothesis and establish generalizations or conclusions.
Determine the best way to present the outcomes of the data gathering, testing and conclusions.
If the hypothesis is rejected, reflect on possible modifications.
Decide on the research issue:
Identify the topic or issue
Locate a range of sources
Frame a research question or hypothesis and select the research techniques.
Conduct the research:
Gather data, collect evidence
Analyse and evaluate evidence
Produce findings.
Make judgements:
Make decisions or draw conclusions
Evaluate and justify.
Examples:
1. Rates of reaction, e.g. mass loss of calcium carbonate reacting with acid, calculate initial rate of reaction, change concentration of acid or initial temperature.
2. Effect of temperature on the solubility of a salt, changes of the solute, different temperature ranges.
3. Charles' Law experiment, measuring the circumference of a balloon at different temperatures to calculate volume.
4. Investigate the effect of surface area to volume ratio on cell size.
5. Investigate the effect of solute concentration on osmosis in plant tissue.
6. Investigate the effect of temperature on plant cell membrane.
7. Investigate how the reaction rate of an enzyme can be affected by temperature.
2.3 Report on an experimental investigation
Phase 1 - Planning and experimenting
1. State the problem you are investigating and choose a topic that has a dependent variable that can be quantitatively measured.
2. Gather relevant background information on the topic from appropriate sources and iInclude copies of this information the Appendix 2.
3. Choose a particular aspect of the topic to investigate and state the purpose of the investigation.
4. Develop a hypothesis.
5. Determine the independent variable and state how it will change in the investigation.
6. Determine the dependent variable and explain how it will be measured.
7. List the variables that may affect the investigation and explain how they will be controlled to make a fair test.
8. List the equipment you will need for the investigation.
9. Describe the experimental procedure using a step-by-step outline, detailed enough to allow others to repeat the experiment.
10. Draw a blank data table to record the first hand data you will gather from the investigation.
11. Explain how the safety risks will be managed in the experimental procedure as approved by the teacher.
12. Get teacher approval before continuing with the investigation.
13. Conduct some preliminary trials to determine if there are any problems with the experimental procedure and discuss any necessary modifications.
14. Carry out the investigation, collect the first hand data and record it in the data table.
15. Prepare a written report, using the following report format and checklist: Title Page (Name, Partners, Teacher, Grade, Subject, Due date, Topic, Clip art or pictures).
16. Table of Contents
17.0 Introduction
17.1 Statement of the problem.
17.2 Background information and research on the topic (include in-text referencing).
18.0 Aim
18.1 Purpose of the investigation
18.2 Hypothesis
19.0 Materials and method
19.1 List of all equipment
19.2 Step-by-step outline of how the investigation was conducted
19.3 Photographs, pictures or diagrams of experimental procedures.
20.0 Results
20.1 Organization of first hand data, e.g. tables and graphs
20.2 All tables and graphs have titles and are labelled (e.g. Table 1, Figure 1)
21.0 Discussion
21.1 Start with a statement of what the results indicate about the answer to the problem you are investigating.
21.1 Compare the results with the hypothesis.
21.2 Link the results with the background information and research related to the topic (include in-text referencing).
21.3 Explain any weaknesses in the experimental procedures or difficulties in measurement or sources of error.
21.4 Explain how you could improve the investigation to reduce error.
21.5 State any further investigations suggested by the results.
22.0 Conclusion
22.1 State the findings by relating the results to the aim.
22.2 State whether the data supported the hypothesis or rejected it, i.e.whether you accept or reject the hypothesis.
23. Bibliography
24. Acknowledgements list of the people who helped you and how they helped you.
25. Appendix 1: Phase 1: Planning & Experimenting
26. Appendix 2: Copies of secondary data sources used to provide background information.
2.4 Science, Maths and Technology
Science is concerned with gathering information by investigation reorganizing the information to get patterns and regularities looking for explanations and communicating findings to others.
Finding patterns and regularities simplifies the descriptions of observations.
Observations are information gained by using the senses.
Investigations may be qualitative requiring general observations or quantitative requiring counting or measuring.
Science teachers should conduct investigations so that the students can observe phenomena before listening to interpretations.
The teacher should not say too much, but should let the experiment speak for itself.
Effective teachers select content, skills and learning experiences in the subjects they teach that will foster students intellectual and personal growth.
Teachers should be able to express subject aims and goals for what students should expect to gain from their learning experiences and organize subject content coherently and at a level that is appropriate to the student group and their learning.
This document contains ideas on practical teaching for the trained science teacher.
After choosing an experiment from this book, the teacher should practice the experiment before demonstrating it to students or before requiring students to do it.
The teacher has the duty of making the decision about whether the experiment is safe for the children in the class.
2.5 Biology experiments, artificial and concomitant variation
1. The method of artificial variation.
Manipulate one variable to note the effect on the other variable, e.g. What is the effect of temperature (the manipulated or independent variable) on the enzyme digestion of starch (the dependent
variable)?
2. The method of concomitant variation, a correlation method.
A naturally occurring variation in some condition (Variable 1) is correlated against another condition (Variable 2).
Nature has manipulated the variables, but you can class one variable as dependent and one variable as independent.
Examples include the following:
2.1 Do young leaves have the same density and distribution of stomata as older leaves?
2.2 How does temperature in a natural environment affect stoma opening?
You do not need you to control the environmental temperature, but you do need to measure the dependent variable at different temperatures.
The problem is the control of other potentially influential variables, e.g. humidity.
One way to address the confounding variables, e.g. humidity, is to collect data on the other variable as well.
So call the stoma / temperature data Part I, and call the stoma / humidity data Part 2, then run the statistics on each pair separately.
2.6 Biology experiments, use of live animals
Biology experiments have special ethical and practical problems.
1. Students and the local community may be upset if they think animals suffer during experiments, e.g. fish and frogs.
2. Human saliva, human cheek cells, human whole blood from a hospital source, and human teeth scrapings may transmit diseases.
The use of body fluids for secondary school experiments is not favoured nowadays so many laboratory experiments are now being done with artificial solutions.
Do not take blood samples from staff or students.
3. Studies of living mosquitoes may risk transmission of malaria and other diseases.
4. Most animals can inflict bites so handle them with great care.
Animal bites may transmit infections and animals may carry human parasites.
5. Treat dissection material as if it is contaminated.
Dissecting instruments must be sterilized before use.
6. Vermin and the insects are attracted to animal food.
Mouldy and decaying animal food and animal wastes may be health hazards, because of the presence of bacteria and other micro-organisms.
7. The teacher must answer the following questions about using live animals:
* Is it essential for live animals to be kept?
* Have alternatives to animal experiments been investigated?
* Has the number of animals been kept to a minimum?
* Will the animals be housed under appropriate conditions?
* Who will take responsibility for feeding and caring for animals during holiday periods?
* Have procedures been established for the safe handling of animals to reduce the risk to staff and students of being bitten or scratched?