Tai chi for older nurses

1. Type of sampling

1.1. Convenience sample

2. Threats to internal validity

2.1. Selection bias

2.2. Instrumentation: possible errors in recording productivity

3. Sample

3.1. Nurses, 40 years old or older

3.2. Able to participate for 15 weeks

3.3. Currently moving patients

3.4. At least one year experience

4. Population

4.1. Female nurses, average age=54.4

5. Threats to external validity

5.1. Small pool of participates, are they representative of nurses as a whole?

6. Research design

6.1. Randomized Trial