Data Collection and Processing, aspect 1

By Tuesday, November 2, 2010 , , , , 0

Today, we will move away from Design and consider ‘Data Processing and Presentation’ (DCP) aspect 1.

DCP is all about collecting raw data, displaying it and processing it.

DCP aspect 1 deals with correctly and accurately presenting raw data.

Data should be put into a table with a title.

Any raw data collected can be split into qualitative (an observation – eg, I saw some bubbles) and quantitative (eg, 30.5 oC). Tables of data should contain both quantitative and qualitative observations to achieve a ‘c’.

The quantitative data should be put in columns with headings, units and the associated uncertainty for the piece of apparatus.

A good rule of thumb to apply for the uncertainty of the apparatus is to use + / – half the smallest division for ‘analougue’ pieces of apparatus and the smallest division for ‘digital’ pieces of apparatus.

For example, a measuring cylinder (an analouge insterument) may record to + / – 0.1 cm3. Therefore, the uncertainty is half of this value, in other words + / – 0.05 cm3.

A digital balance may record to 0.001g, so the uncertainty is 0.001g.

The value that is being recorded should be of a consistent number of significant figures as the uncertainty.

For example, coming back to the measuring cylinder, volumes such as 3.15 cm3 and 3.10 cm3 are acceptable but not 3 cm3 or 3.1 cm3.

Tomorrow, DCP aspect 2.


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