Analysing critically

How do I teach students to critically analyse their data?

Watch a group of students discuss their investigation into the effectiveness of a sport drink and note the issues that arise in the analysis of their data.

Here is a set of questions to give students as they independently analyse their results. The answers to these questions will indicate the reliability of the data and therefore the degree of certainty with which a conclusion can be drawn.

1. Is the data consistent or is there a set or single piece of data that is not consistent with the remainder of the data? As much as students may wish to, unusual results are part of the data set and DO need to be included. Maybe a few more trials could be performed to see if the variations continue.

2. How large are the variations compared to the overall size of the data being collected? If students are measuring crater diameters that are in the vicinity of 2 cm, is the variation more or less than 0.5 cm? that is. do the majority of readings fall between 1.5 and 2.5 cm? Are there any outlying results and what might be the cause of these? Are the measurements being taken with extreme accuracy? The sloppier the measuring, the more likely there will be variations. Were the measurements always taken in the same way..., by the same person...? Were there any variables that may not have been satisfactorily controlled?