1. Methods of Data Collection

Why collect data?

Types of variable

Problems in data collection
- Objectivity
- Reactivity

Sampling: Problems and methods
- Representative and unrepresentative samples
- Methods of sampling

Measurement
- Why measure?
- Scales or levels of measurement

Test Questions

2. Summarizing Data

Why summarize data?

Typical scores
- Mode
- Median
- Mean
- Which should we use?

Measures of spread
- Range
- Interquartile range
- Standard deviation
- Which should we use?

Test Questions

3. Visualizing Data

Why visualize data?

Stem-and-leaf diagram

Graphs of distributions
- Histogram
- Frequency polygon
- Box-and-whisker plot
- Bar chart

Test Questions

Graphs of relationships
- Scatter plot
- Line graph

Information required in graphs

Test Questions

4. Correlation and Association

What is correlation?

Two types of correlation coefficient
- Pearson correlation
- Spearman correlation
- Which type of correlation should we use?

Interpreting correlations
- Correlation and prediction
- Relatedness not equality
- Correlation not causality
- Relationships that are not straight lines
- Range restriction

Test Questions

5. Standard Scores and the Normal Curve

The Normal distribution

Standard Scores

Test Questions

6. Statistical Inference

Why do we need statistical tests?

Probability and chance

Three requirements for confidence

Statistical significance

Directional and non-directional tests

Test Questions

7. Statistical Tests

Why use statistical tests?

Types of data

Counted data: Chi squared

Measured data in pairs
- An example
- One sample t-test
- Wilcoxon test
- Sign test

Measured data not in pairs
- An example
- Two-sample t-test
- Mann-Whitney test
- Median test

Test Questions

8. Necessary Skills

Interpreting statistical formulae

Using statistical tables

Test Questions