The ideal method to use is a comparison group where data is collected from two identical groups at the start of a program as well as several times throughout the implementation of the program. This is also the most difficult method to use and requires extensive resources. A general rule of thumb is to use the most rigorous method based on the resources available. Data collection tools must be designed to obtain the information required by the evaluation questions. Interviews are used to obtain testimonials to how much participants like the program or how they have changed while participating in the program.
Observation provides information through direct observation of behaviors.
It is recommended to use existing standardized instruments when possible because the reliability and validity has been determined through pilot testing. Results will be most conclusive when outcomes are measured using more than one instrument or method. Generally, data analysis techniques will be determined by the evaluation questions and the methodology used to collect data. Data analysis can be as simple as calculating percentages or as complex as performing a time series or regression analysis. However, be aware that more complex analysis usually requires assistance from someone who has expertise in data analysis.