Lab+write-up+(internal+assessment)

Making tables and graphs on Excel and Numbers
**Excel (PC or mac):**
 * [|making a table]
 * [|making a graph]

**Numbers (mac only):**
 * [|making a table]
 * [|making a graph 1]
 * [|making a graph 2]
 * [|transferring tables and graphs to a document]

t-test statistical analysis
Many times in science, we want to know if two sets of data are //really// different. For example, if a drug is used to treat one group and a placebo is used for another, is the affect of the drug different enough to be statistically significant. One way to do such an analysis is with a t-test.

If you would like a more comprehensive explanation of the t-test, read this. However, for our purposes it is important to understand the test's basic use. Using an online calculator enables you to come up with a number that is the probability (//p//) that two sets of data are different. By convention the cutoff is usually <.05 (5%). That is, if //p// is less than 5%, there is a less than 5% chance that the two groups are the same with respect to the variable being studied.

We won't go into one tailed vs. two tailed t-tests. For our data, use the two tailed test. One thing we do need to consider is whether the groups are paired/matched. The groups are paired if each individual is subjected to the two independent variables. In most of your experiments with the EMG, this is the case because you tried two different procedures on 4-10 individuals.

Student's T-Test Free online t-test calculator

- David McCandless: The beauty of data visualization - GapMinder World