This is the final blog in the series, designed to help primary teachers start the development of their learners’ scientific enquiry skills. Although a lot of words have been written and there are lots to ideas to assimilate, I hope you have gained an insight into each of the transferable skills and their progression throughout a learner’s journey through the primary years, as well as some useful strategies to nurture enthusiastic young scientists.
The skill of evaluation is covered last, as it is most frequently introduced at the end of an enquiry – a time to reflect on how the enquiry went. This should include a review of the procedure used to generate any data collected, and also a consideration of conclusions drawn. Like ensuring time is planned for drawing conclusions, time is also needed for a meaningful evaluation.
This is not to say that evaluation is a skill only used at the end of a enquiry. Often the best time to evaluate a method is when leaners are actually carrying out their practical. Always look for opportunities to ask learners if they could improve what they are doing – it is easier to evaluate a procedure when it is taking place than thinking retrospectively.
Why is the skill of evaluation an important ‘life skill’?
The skill of evaluation is becoming increasingly important as ‘thinking skills’ gain a foothold in the primary curriculum.
Giving learners the time to:
- reflect on their own performance,
- evaluate strengths and areas to develop, and
- set targets to improve future performance,
are seen as crucial skills for life-long learners. As such, scientific enquiry can play a major role in the cross-curricular delivery of the skill of evaluation.
What can we expect in early attempts at evaluation?
As soon as young learners start to engage in explorations and experiments, we should encourage them to think back on how they went about their work.
Early evaluations will tend to focus on their own performance as learners (e.g. “I shouldn’t have been so noisy!”). However, with our guidance we can prompt an opinion about their performance as young scientists (e.g. “I shouldn’t have pushed the toy so hard.”). This can be followed up by asking “Why?”, in order to stimulate some deeper explanation. So as in other skills, such as predicting or concluding, whenever improvements are suggested the associated reasoning should be asked for.
How can our approach encourage the development of evaluation?
Discussing your general observations with the whole class regarding their gathering of data made during an enquiry, helps to clarify what is needed in a scientific evaluation.
The learner who can focus on improvements to an enquiry and say why it would be better next time can then be prompted to explain how those improvements could be brought about. An appreciation of the quality of data collected in repeat observations and measurements is also starting to develop by the end of primary education.
Here are some strategies for you to consider:
STRATEGY 1 – Start your learners early!
Even though the skill of evaluation is considered a higher order thinking skill, it is good practice to start learners thinking about and commenting on their working methods as early as possible.
At first this will be very directed, as the teacher illustrates the skill and asks questions that stimulate evaluative statements appropriate to the age of the class.
These questions show the how to promote early progression in the skill.
- “Could you have noticed anything else about the tree bark?
- Could you have looked more carefully?” (Evaluating the observational skills).
- “Did you mark each person’s hand-span carefully from the end of their thumb to the end of their little finger every time?”(Evaluating measuring skills)
- “Are you sure this ball is bouncier than that one?” (Evaluating the comparisons between two objects).
- “Was it really a fair test between each piece of paper you dropped?
- How could you have made it better?” (Evaluating the recognition of simple fair tests).
STRATEGY 2 – Comment on poor practice
It is often easier to teach the skill of evaluation when children are focusing specifically on this specific skill. Therefore, as when we develop skills of planning fair tests, we can deliberately provoke an evaluative response from children by demonstrating poor methodology.
- Making cursory observations of objects, rushing through each one
- Not judging things carefully when collecting series of data
- Measuring with a large gap between your eye and the scale on the equipment
- Making sure you carry out an obviously unfair test
By Stage 3 some learners will be ready to start looking at scenarios of obvious poor practice presented to them on a worksheet and to comment critically.
STRATEGY 3 – Practise the skill of evaluation
Learners can consider their method of working and also its impact on the validity of their conclusions. At Stages 5 and 6 their working methods are sufficient, together with practical suggestions about how they could be improved.
Here are some elements to consider:
- The individual actions performed in any testing (such as the accuracy or precision of their measurements).
- For example, the accuracy of readings is not always determined by the precision that is possible with a measuring instrument. It is not always the case that the most finely tuned measuring instruments provide most accuracy.
- For example, when investigating sugar dissolving, children often want to use stop-watches that read to one hundredth of a second. However, it is impossible to judge accurately when the last grain of sugar dissolves. Therefore, giving such precise readings as 36.78 seconds is inappropriate in some instances.
- The fairness of tests. In investigations where we manipulate variables, we should consider if the control variables have been kept constant in each test.
- In enquiries in which we cannot control all the variables that might have an effect, we should consider if the size of the sample chosen was large enough to draw meaningful conclusions. This is required in many biological enquiries.
STRATEGY 4 – Encourage a variety of methods when tackling the same problem
When giving opportunities for older primary children to plan their own work, there will inevitably be different suggestions as to how to tackle the practical work. Provided your resources permit, encourage different groups to try different methods. Then you can compare results obtained using the different methods.
For example, when investigating which paper towel is most absorbent we have groups that might choose to:
- spill some water on a desk and mop it up
- dip the paper towels into shallow water and measure how far it rises in a certain time
- measure how much water soaks through a paper towel starting with the same volume of water each time
- start with a set volume, dip the towel in, then see how much water has been absorbed
- weigh the paper towel before and after dipping in water, etc …….
In a plenary session, groups can show other how they performed their tests and discuss the advantages and disadvantages of each method as a whole class. Any differences in the conclusions drawn from each group can be evaluated in terms of their differing methods.
If the data from all the groups points to the same conclusion, we have good evidence that the conclusion drawn is valid one.
- Think of two or three general questions to prompt children when evaluating an enquiry.
- Think of a question or two to stimulate evaluation in the next science enquiry you plan to carry out with your class.
- Think of an enquiry in which taking repeat observations or measurements would be useful. Why do you tend to get variations within a set of repeat results in the enquiry you have considered.
- What difficulties have you come across when developing children’s skills of evaluation?
- Think of an enquiry that you will be tackling with your class in the future and devise a demonstration modeling activity of poor practice to stimulate an evaluative response in preparation for the task.
- Do you always get time to evaluate the method used to collect evidence? How can you create time for this essential skill?
- Do children record their evaluations as a routine section in writing up enquiries? If they haven’t got time, which other part of a report could you sacrifice in order to develop this skill?
- How often do your class evaluate the fairness of the tests they have carried out? Do they ever consider sample size as an important aspect of some scientific enquiries?
- Can you think of an enquiry that always produce a variety of suggestions when you ask children to plan their own investigation?
- Choose one enquiry and brainstorm as many ways to tackle it as you can. Will some methods produce more valid conclusions than others?