Conservation Test

Conservation Test
This has a total of eight items.
Number
1 You have six eggs and six egg cups. Child puts one egg in each cup (10cm apart).
• Are there the same number of eggs as egg cups?’ [Child agrees.]
• Take eggs out and bunch them together (5cm apart). Spread cups apart (15cm space).
• Are there the same number of eggs and cups now?’
• If ‘Yes’, ask ‘How do you know?’.
Good explanations include: ‘You haven’t taken any away/put in any new ones’ or ‘There are still the same number of each’ — i.e. some sense of necessity. If the child counts both eggs and cups, this does not count as a good explanation.

2 From a collection of ten or so red and green chips, select six red chips and lay them in a row (10cm apart).
• Invite the child to choose ‘one green for every one of my red chips’ and lay them in a row next to the red ones. You can help them do this.
• Child agrees there are the same number.
• Bunch red chips together (5cm) and spread green ones apart (15 cm). Questions and analysis of responses as above.

3 Measurement of amount (otherwise ‘mass’, ‘amount of stuff’, etc). You need one tall
250 cm3 beaker (A), one squat glass dish of similar volume (B) and one small 50 cm3 beaker with line 0.5cm from top (C) (see Figure 1.2 on page 9).
• Fill C to the line, pour the water into A and repeat this twice more. Explain what you are doing, get the child to count. Then C filled to line and poured into B, three times again. Child agrees same measurement poured into each of A and B three times.
• ‘Look at the two glasses (A and B). Which has more water, or are they the same?’ Test with counter-questions (‘Another child I showed this to said …’, ‘Why do you think so?’, ‘If they were orange juice, and you could have one, which would you have?’, ‘Why?’, etc).

Solid substance

4 You have two plasticene balls each of 5cm diameter.
• Let the child handle them, and get him or her to agree that both have the same amount of plasticene.
• Now change one into a sausage shape. ‘Remember what we did. We had two balls the same, then we rolled one out to a sausage shape. Is there now the same amount of plasticene in this one and that [the original] one?’
• ‘Why do you think so?’
• ‘Another child told me she thought there was the same/a different amount, what do you think?’
5 Re-form the ball from the sausage and re-establish equivalence. Now flatten one into a pancake (10cm diameter) and repeat questions.
6 Re-form, establish equivalence and then make one into five little balls of approximately the same size. Repeat the questions.

Good explanations again involve some sense of necessity: ‘You haven’t taken any away, added any, it’s still the same amount; it’s longer but it’s thinner…’ and so on.

Weight
Start again with the two balls of plasticene.
Put one on each side of a balance and ensure child agrees that they are the same weight.
7 Transform one into a pancake as before, and ask if it still has the same weight.
8 … and into five small balls; again focus on weight.