Asia-Pacific Forum on Science Learning and Teaching, Volume 5, Issue 3, Article 8 (Dec., 2004)
Yeung Chung LEE and Pun Hon NG
Hong Kong primary pupils' cognitive understanding and reasoning in conducting science investigation: A pilot study on the topic of "Keeping Warm"
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As data analysis of the other tasks is still going on while writing this paper, we presented only the results of the "Keeping Warm" task in this preliminary report. The data were obtained from one Primary 4 class of School A, and two Primary 5 classes, one of School B and the other of School C. The data was obtained from 22 groups, totally 99 pupils. All pupils did not have experience in carrying out scientific investigations before the study. However, they should all have acquired some basic concepts of heat flow and heat loss when they studied General Studies in Primary 2. The data obtained through observation, facilitator-pupils exchanges, and pupil worksheets were categorized and presented in three headings: planning, implementation and evaluation. Tables 1 and 2 show different categories of pupils' performance by grade levels in respect of planning and implementation of the task. Since pupils planned the investigation and collected data in groups, the data were reported in terms of number of pupil groups. Table 3 shows the pupils' evaluation of experimental design and results. As this part was performed by individuals, the data were reported in terms of number of students. The categories in the three tables were set up to reflect the characteristics and peculiarities of pupils' reasoning with regard to the three aspects of investigation.

Pupils' performance during planning Number of pupil groups
Primary 4 (N= 8 ) Primary 5 (N= 14 )

Control of variables

1. Used the same volume of water for all cups 4 10
2. Put the thermometers into the three cups at the same time for measuring the initial temperature   1
3. Added water to the three cups at the same time 1  
4. Checked that the temperature of the three thermometers was the same before putting them in the water.   2
Measurement of dependent variables
1. Measured the initial temperature 1 2
2. Took one temperature reading after an unspecified time period (e.g. after a while) 2
3. Took one temperature reading after a specified time period (e.g. 5 minutes) 4 11
4. Took temperature readings at regular time intervals (e.g. at five-minute intervals for 15 minutes) 1 3

Table 1: Pupils' performance in the planning of investigation

Pupils' performance while implementing their plan Number of pupil groups
Primary 4 (N= 8 ) Primary 5 (N= 14 )
Deviations from their original plan
1. Included extra steps to improve validity of the results    

a. Measured the initial temperature


b. Measured temperature at regular time intervals


c. Used equal amount of water for all cups

1 3

d. Recorded time


e. Emphasized adding water to the cups as quickly as possible to reduce heat loss

2. Omitted part of the steps, hence affecting validity of the results 1  

a. Failed to take time


b. Forgot to take temperature readings after the specified time lapsed

Introduced erroneous variables that affect the reliability and validity of the results
Touched or held the cups in their hands frequently; stir the water with the thermometer; touched the water while waiting; took out the thermometer occasionally 3 2
Incorrect use of apparatus
Took out the thermometer out of water to read the temperature 2 1
Manipulation of experimental procedure to match the results with their prediction
1. Took out the thermometer and place it in their hands to elevate the temperature 1  
2. Extended the wait time or repeat the experiment hoping to get the predicted results. 1 1

Table 2: Pupils' performance in implementing their plan

Pupils' evaluation of experimental design and results Number of pupils
Primary 4 (N= 37 ) Primary 5 (N= 62 )
The design was inadequate or the results were inaccurate because:
1. Variables not adequately controlled .

a. Different volume of water in different cups;


b. Water not added to the cups at the same time;


c. The temperature shown by the three thermometers is slightly different; should use the same thermometer for all three cups.;


d. The cups were of different thickness, size, or width;

4 1

e. Influence of the environment, e.g. a fan on the ceiling, air-conditioning;

3 2

f. Should not hold the thermometer with hands while waiting

2. Technical errors
Spilling of water onto the table while pouring water into the cups; difficult to read the thermometer accurately; too much delay in handling the hot water due to excessive arguing over the procedure; inaccurate measurement of volume of water 4 1
3. Quality of data
Failed to measure the initial temperature 2
4. Inconclusive nature of the task
Argued to use more cups for comparison; inconclusive to use three cups only 1
5. Results not consistent with pupils' own predictions
The observed results were not the same as pupils' predicted results. 9
The design was adequate or the results were accurate because:
1. No reason given 6 10
2. Fit with pupils' preconception (e.g. hard plastic is not a good conductor) 4 1
3. Good design; results would not be affected by other factors;   1
4. Took measurements with measuring instruments, predominantly thermometers 9 13

5. Good quality of data (Measure temperature at regular intervals)

6. Support from common sense reasoning (The cups are made of different materials, therefore there should be a difference in the results.)   5
7. Personal attributes (E.g. We worked very carefully and systematically.) 1 1
8. Misconception of the nature of scientific inquiry (It must be accurate because it is an experiment.) 3  
Further improvement to experimental design to improve the validity and reliability of the results

a. Lengthen the time of observation

3 2

b. Use hotter water (e.g. 100oC)

1 2

c. Add more water to each cup


d. Test other cups made from different materials


e. Can use my own hand instead of the thermometer to measure temperature (Primary 4)


f. Use a lid to cover the cups


Table 3: Pupils' evaluation of experimental design and results


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