Design and
purpose
of the
research

Quantitative
and
qualitative
data

Design
alternatives

Aids

Experiments

Experiments are a powerful way of testing hypotheses. In its simplest form, the researcher seeks to learn whether, under carefully controlled conditions, a change in one variable produces a hypothesized effect on some other variable.   Careful procedures are followed to rule out, to the extent possible, the influence of anything that could affect the outcome of the experiment.

Experiments can be conducted under carefully controlled conditions in a laboratory or in natural social settings. Grotberg and Badri (1986), for example, conducted an experiment to test whether the developmental level of young children could be accelerated by teaching their mothers how to provide additional stimulation for their children. The authors reported evidence of greater development among children whose mothers participated in the experiment compared with children whose mothers were not given the special instruction.

Designs based on qualitative data

Qualitative data can be obtained under almost any design, but we will describe briefly only three designs frequently used with qualitative data. These are field or observational studies, case studies, and focus groups.

Field or observational studies. Field study methods were developed by anthropologists who studied isolated and generally preliterate societies. Their techniques have spread to investigations of behavior in many kinds of social settings, including business organizations, informal organizations such as clubs, and many other groups with distinct membership and activities. Data collection is based on a combination of data gathering techniques. The investigator observes, listens to what people talk about, asks questions, and records what he or she sees and hears. A detailed record is kept of everything that is observed and discussed. Any available data are analyzed as well. The investigator continuously reviews his or her data and seeks to develop an understanding of why the behavior being studied occurs in the way it does. Analysis is based on the investigator's skill and creativity in organizing and drawing meaning from the mass of data that is collected.

Case studies. In a case study, the investigator selects a group for intensive study. The case study method can be applied to a single individual, a community, a region of a country, or to any organization. A combination of qualitative and quantitative techniques is used to collect data. These might include observation, informal interviewing, surveys, and analysis of existing data and records. The objective is to provide a comprehensive, integrated description of the essential features of the case being studied. While only one or a few cases are studied in any single investigation, the case study method often produces greater richness and greater depth of understanding than can be obtained by surveys.

Focus groups. A focus group is a group of persons brought together by an investigator to learn how the persons feel about some issue or topic. A group of 8 to 10 persons is assembled by the investigator and asked to discuss a selected topic. The investigator or a trained facilitator conducts the discussion, which really is a kind of group interview. The topic is introduced and members of the group are encouraged to voice their views and opinions. The discussion is recorded, often by a tape recorder, or by hand, and then analyzed. Focus groups are an excellent way for exploring a topic, testing the meaning of terms or concepts, and for refining hypotheses.

Other design decisions

We have provided only brief descriptions of some common designs and research techniques. For further discussion of various kinds of research designs and their features, go to Designing Designs for Research. Although this site focuses on evaluation of programs, it covers basic elements of design and illustrates features of many commonly used designs. It also includes some designs we have not discussed in this chapter.

Two other sets of decisions have to be made in creating a research design. These involve constructing ways of measuring the variables you want to learn about and selecting the sample from which data will be obtained. These points are covered in the following two chapters.