The success of the data collection phase often depends on the quality of the planning stage. How long data collection will take depends on the type of evaluation being conducted and indicators being collected (process, outcome, or impact).
Some of the most common approaches to collecting data are surveys, observation, interviews, and focus groups.
- Surveys rely on data collected through questionnaires or interviews. Surveys can be administered electronically, on paper, via telephone, or in person.
- Observation of individuals who have been exposed to a program can be used to assess "before" and "after" differences. For example, one could observe service practices at a retail establishment before and after the administration of a server training program.
- Interviews conducted in person can be structured, semi-structured, unstructured, or in-depth:
- Structured in-person interviews are the same as questionnaire administered in-person interviews and adhere to specific questions;
- semi-structured interviews allow more freedom to ask for additional information or clarification;
- Unstructured interviews are even less restrictive. This type of interview is more conversational and is often used in exploratory research where little is known or understood about the topic of interest;
- In-depth interviews allow an interviewer to go deeper into a particular topic of interest to cast light on a particularly successful or unsuccessful approach or activity, for example, in-depth interviews can help to determine the reasons for a high attrition rate.
- Focus groups are often used in the pilot phase of a program to gauge opinions and sensibilities and identify likely outcomes and reactions by the Target audience so that the appropriate program design and evaluation instruments can be developed.
- Review the Data Collection Approaches supplementary page for an overview and examples of each of the approaches listed above.
Regardless of the approach used, the data must be uniformly collected across time points.
- When conducting pre- and post-intervention assessments, it is important that the same instrument be used at each time point in order to assess change over time.
- Where feasible and appropriate, data can be collected from a control or comparison group-who have not been exposed to the intervention, but are similar to the intervention group in key characteristics-in order to make comparisons.
- This important topic, one of the key "Issues to Consider" in the Evaluation section, is covered in greater detail in the Importance of Maintaining Uniform Data Collection Procedures page.