Robert Fettgather holds a Ph.D in Psychology and Masters degrees in both Psychology and Special Education and received the Distinguished Alumnus Award from West Valley College. Robert Fettgather has served as Special Consultant in psychometrics to the Departments of Education and Developmental Disabilities for the State of California. He holds a specialist credential in learning handicapped and community college credentials in both psychology and developmental disabilities.
The goal of scientists who study human development is to produce observations and explanations that can be applied to a wide an age range of human beings. Additionally, they study cultural expectations; make predictions about development and use the scientific methods to test them. Ideally, research findings can be used to positively influence development in individuals. Sometimes findings are compromised with various forms of bias.
Descriptive research methods are used to study the relationship between variables. Case studies are in-depth examinations of single individuals. The naturalistic observation is a research tool in which a subject is observed in its natural habitat without any manipulation by the observer.
Surveys collect data about attitudes, interests, values, and various kinds of behavior. Simply put, a survey consists of a predetermined set of questions that is given to a sample. With a representative sample (one that is representative of the larger population of interest), researchers can describe the attitudes of the population from which the sample was drawn. But polls and surveys can be quite inaccurate- note the problems with political polls and the 2016 election when pollsters got the whole thing wrong!
Correlational studies measure the relationship between variables. To test causal hypotheses, experimental designs in which subjects are assigned randomly to experimental or control groups are necessary. A key to experiments is the independent variable- the variable that is manipulated by the researcher. The dependent variable is the response that is measured.
There are three options for studying age-related change: a cross-sectional design to study different groups of people of different ages; a longitudinal design to study the same people over a period of time; and a sequential design to combine cross-sectional and longitudinal designs.
Cross-cultural psychology is the scientific study of human behavior and mental processes under diverse cultural conditions. The two primary goals of cross-cultural research are to identify universal changes that cross cultures and to gain information that will help improve people's lives.
Critical thinking can help uncover potential bias that complicates research. Bias is a predisposition or prejudice toward something. For example, we discussed sampling- a sampling bias occurs when the sample is not representative of the general population. Selection bias occurs when the participants in the sample are not equally and fairly selected for both the experimental and control groups; this renders any results from the experiment almost meaningless. An example of response bias occurs when only highly motivated people return a survey. When this happens, the resulting data is biased toward those with the motivation to answer and submit the survey, and is therefore not representative of the population as a whole. Researcher bias is a misrepresentation, intentional or not, of the data.
