SAASTE Science/Guidelines for Scientific Investigations
| SAASTE Science |
| Scientific Method - Guidelines for Scientific Investigations - Ideas for Class Projects - Radon Measurement - Road Markings |
Guidelines for selecting suitable investigations
editHow do I go about selecting and initiating a suitable investigation for my learners?
Many investigations deal with the selection of the appropriate materials to perform a particular function e.g.
- Perform an investigation to determine which material is best for insulation purposes
- Perform an investigation to determine which material is best to create a specific structure or product.
Investigations concerning events in the school's immediate surrounding should also be considered. The following is a suggested route for the educator to assist his/her learners in arriving at a suitable investigation: Perform a few focus tasks to improve the learners' observational skills. One must bear in mind that observations can include all five senses (taste, touch, hearing, sight and smell).
A possible way of improving observation in terms of hearing:
- pair learners
- one learner from each pair is blindfolded
- one learner leads the blindfolded learner
- the blindfolded learner mentions all the sounds he/she hears and reports happenings in the surroundings to the other learner who records it on a sheet
A possible way of improving observation in terms of touch:
- put different objects in a container
- learners identify objects in the container by means of touch only (learners are not to see the objects in the container)
A warning in the case of tasting: This observational skill should be practiced under controlled circumstances
Once the focus tasks on observation have been completed the educator can ask learners to prepare a list of events which occur in their immediate surroundings e.g.
- Gardening
- Making a noise
- Working
- Littering
Ask the learners to indicate what events they are happy or unhappy about - this will lead to problem identification.
A hypothesis can then be formulated.
The extent of the problem can then be determined quantitatively, which implies that measurements have to be made.
The educators now have to assess whether the measurements can be performed within a reasonable time frame.
If the outcome of this assessment is positive the educator can confidently go ahead with this investigation, knowing his/her learners will be exposed to the majority of the science process skills.
A look at a few science process skills:
|
ACTIVITY |
PROCESS SKILLS |
DESCRIPTION |
|---|---|---|
|
Literature research on gastric antacids |
-Interpreting information |
-Cross referencing. -Finding information in books -Organising information |
|
Stating Hypothesis - Gaviscon will increase the pH of gastric acid fastest |
-Hypothesizing -Predicting |
-Making a prediction using prior knowledge or information |
|
Study design -Add solutions of different pH values into four beakers -independent variable: time -dependent variable: pH |
Planning science investigating |
-Identify variables -Controlling variables i.e. change one variable while keeping the other constant (temperature etc.) -Plan how to measure variables |
|
Experiment -Add same volume of different antacid to each solution -measure change in pH as a function of time -record change in pH for every solution on a sheet |
-Conducting investigations -Measuring -Observing and comparing |
-Measurement of variables (time, pH etc.) -Observe changes in dependent variables (pH etc.) -Recording data on sheets -Report observations |
|
Recording data -record changes in pH against time for each solution |
-Sorting and classifying -Recording data |
Recording data in the form of tables, graphs, sheets etc. |
|
Analysing and interpreting data |
-Comparing data |
-Look for patterns and tendencies in data |
|
Conclusions |
-Conclusion |
Stating whether the hypothesis has been proven to be correct or not |
References:
editText books
editBunge, M. (1967) Scientific Research I - The Search for System - Springer-Verslag Berlin Heidelberg New York
Petrucci, R.H. (1985) General Chemistry: Principles and modern applications. 4th edition: Macmillan Publishing Company. New York.