Data Collection For Evaluation
In the data collection phase of an evaluation, evaluators compile information needed
to answer the evaluation study questions that have been identified in the earlier
design phase. In the design effort, evaluators reviewed the evaluation questions,
noting what data would need to be collected from whom in order to answer the questions.
Next, evaluators decided what approaches or techniques would best provide them with
Many correctly think of evaluation as an investigative process and data collection as
"gathering credible evidence" to indicate how the program is performing or has performed.
The evaluator, with involvement from the client and stakeholders,¹
selects those approaches and techniques that are feasible within the time and budget constraints of the
project to answer the evaluation study questions. The intent is to collect information that
stakeholders perceive as trustworthy and relevant. Evaluators consider respondent
burden, collecting only the type and quantity of data needed to answer the study
questions. Evaluators strive to collect data in a systematic, comparable, uniform,
precise, clear, and unbiased way so that data are correct, complete, valid, and unbiased.
There are many ways to collect data, such as: surveys, document analysis, observation,
interviews, focus groups, etc. Evaluators must choose the best approach or combination
of approaches that best answer the evaluation questions. Quantitative (data in the form
of numbers) and qualitative (data in the form of words) data both have their advantages
and disadvantages. A good option is to consider using both, as they can complement each
other. Usually, evaluators collect qualitative data to add depth and a fuller understanding
of the complexities of a program to the quantitative information that straightforwardly
defines the program. Therefore, careful consideration will be given to data collection
during the evaluation design phase.
A brief description is provided below for the main
Program Evaluation and Improvement Staff (PEIS) data collection approaches:
Documents are very handy in program evaluation. Existing (archival) records often provide
insights that cannot be observed or noted in another way, if the documents are accessible
and accurate. Examining records requires that the data collector have a very clear idea
of what information is needed, because there will likely be plenty of other interesting
information to distract the unorganized reviewer.
Surveys use data collection instruments, like questionnaires, to collect data from a sample
of the relevant population, or from the entire population (a census). Surveys are used
extensively in evaluation - perhaps overused - because of their flexibility to gather data
on almost any issue. When done correctly, surveys are an efficient and accurate means of
collecting data, but they can be difficult to construct, and may yield low participation
(response rate). A low response rate hinders the reliability and validity of the information.
The evaluator does not know if the non-respondents would have answered differently, so
including a non-respondent analysis is often important to see who actually responded or not.
Observations can be useful in determining how the program is implemented and provides
opportunities for identifying unanticipated outcomes. Observations can answer questions
on whether or not the program is being delivered and operated as planned. By directly
observing operations and activities, the evaluator can enter into and understand the
situation and context. However, observation (obtrusive and unobtrusive) can be expensive
and time consuming. Depending on the situation, the observer may need to be a content
expert to accurately interpret the observations.
Interviews are essentially conversations between the evaluators and their respondents.
An interview is selected when interpersonal contact is important, when opportunities for
follow-up of interesting comments are desired, when the topic is complex and requires
explanation and interaction, or when cultural, educational, or language barriers are
present. The use of interviews as a data collection method assumes that the
participants´ perspectives are meaningful and knowable. The quality of information
obtained is largely dependent on the interviewer´s skills and personality.²
Groups (such as focus groups) combine elements of both observation and interviewing.
A focus group is an interview with a gathering of 8 to 12 people, but uses group interaction
to generate data and insights that would be unlikely to emerge in individual interviews.
The technique includes observation of group dynamics, and insights into the respondents´
behaviors and attitudes. Originally used as a market research tool to learn the appeal
of various products, the focus group method has been adopted by other fields as a way to
gather data on a given topic.
"Collect only the information you are going to use, and use all the
information you collect"³
The possibilities for gathering evidence for an evaluation are endless, but unfortunately,
resources are not. Without a coherent plan to answer study questions, people often tend to
collect too much data. By collecting everything from everybody, they hope they will find
something they can use. This wastes resources and is cumbersome to manage. By focusing the
data collection, the evaluator can balance the breadth and depth of the information obtained
and achieve results that are practical and within the budget constraints of the project.
Since all types of data have limitations, evaluators will often select multiple methods to
obtain information that conveys a well-rounded picture of the program. Multiple approaches
and techniques that "triangulate" data from several sources in several ways can improve
overall accuracy and are often seen by the evaluation´s clients as more credible than data
from one source.
PEIS staff are experienced in multiple approaches to data collection and analysis and can
help ensure the most efficient and effective data collection for your evaluation.
1 Stakeholders are persons that have an interest in the project being evaluated or the results of the evaluation. (W.K. Kellogg Foundation. Evaluation Handbook, 1998, page 48.)
2 Patton, M.Q. Qualitative Evaluation and Research Methods, Second Edition, Newbury Park, CA: Sage Publications, 1990.
3 W. K. Kellogg Foundation. Evaluation Handbook, 1998, page 69.