Research Methods 2

Study Block 4

Workshop

Statistical Analysis of Quantitative Data

Aims

• To examine techniques for exploring and statistically analysing quantitative data

• To form an understanding of inferential statistical techniques

• To form an understanding of statistical techniques for measuring levels of association

The Post-Christmas Walking Trial The Trial - An intensive walking exercise programme has been developed to improve

the cardiac fitness of normal subjects.

Subjects - A group of 80 healthy subjects, aged between 20 and 80 years, was randomly selected from the population of Leith.

Study Design - Subjects were randomly assigned to 3 groups, a control, brisk walking and normal walking speed group.

Independent variables - The control group (N=20) did no additional walking. The brisk (N=30) and normal walking (N=30) groups were required to complete a 2 mile walk on a daily basis over a period of 2 weeks.

Dependent variables - baseline resting heart rate was established for each subject prior to commencing the exercise programme. Each subjects heart rate was measured 2 minutes after completing the exercise programme at the end of weeks 1 and 2.

Study Data

You can access the study data in 2 formats

For SPSS

For Excel

SPSS provides more powerful test options but Excel offers greater control over graphs

Trial HypothesesYou should test the following hypotheses using appropriate statistical tests:

1) Within each experimental group, the baseline heart rate values are comparable to typical resting heart rate values (72 beats/Min).

2) The Control group heart rate values will differ with Brisk group values at week 1.

3) The Control group heart rate values will differ with Normal group values at week 1.

4) The Control group heart rate values will differ with Brisk group values at week 2.

5) The Control group heart rate values will differ with Normal group values at week 2.

6) The Brisk and Normal group heart rate values will differ at week 1.

7) The Brisk and Normal group heart rate values will differ at week 2.

Trial Hypotheses

8) The Control group heart rate values will differ between baseline and week 1.

9) The Brisk group heart rate values will differ between baseline and week 1.

10) The Normal group heart rate values will differ between baseline and week 1.

11) The Control group heart rate values will differ between baseline and week 2.

12) The Brisk group heart rate values will differ between baseline and week 2.

13) The Normal group heart rate values will differ between baseline and week 2.

14) The Control group heart rate values will differ between week 1 and week 2.

15) The Brisk group heart rate values will differ between week 1 and week 2.

16) The Normal group heart rate values will differ between week 1 and week 2.

17) Separate group values will differ over the 3 stages of the study.

Additional statistical analysis

1) Explore the association between age and height for all subjects

2) Explore the association between body mass and height for all subjects

3) Explore the combined effects of independent variables on baseline heart rate for all subjects