Nonexperimental designs

Nonexperimental designs • Description is one level of scientific inquiry • Remember • Description • Prediction • Explanation • useful for describing human behavior • but does not allow for prediction • does not allow for causal inference • valuable techniques for certain situations • When you cannot run an experimental design

Before we get into specific descriptive methods we need to discuss a couple of concepts that are important for evaluating any research methodology • Those concepts are • internal validity • external validity • quantitative approaches • qualitative approaches

Internal validity • Internal validity • The degree to which a research design allows us to form causal relationships • experimental methods tend to be high • nonexperimental methods tend to be low

external validity • external validity (generalizability) • Do the findings from a research project generalize to people in real world settings? • nonexperimental descriptive approaches tend to be higher • often done with humans • often done in real world settings. • Experimental/laboratory methods tend to be low • Contrived laboratory settings • Animal research

Thus, • nonexperimental methods tend to be high in external validity, but low in internal validity. • Studying children born to mothers that used cocaine during pregnancy • Experimental methods tend to be high in internal validity, but low in external validity • Studying neonatal rat pups exposed to cocaine.

research designs can also be described as primarily qualitative or primarily quantitative. • qualitative • Written descriptions. • Expressed in nonnumerical terms. • quantitative • Data is expressed numerically

The designs we will discuss in this section are nonexperimental and their goal is to describe. • Tend to be low in internal validity, but higher in external validity. • Also tend to rely on qualitative data • We will discuss four approaches • phenomenology • case studies • field studies • survey research

Phenomenology • Similar to Wundt and Titchener’s introspection. • A description of one’s own immediate experience • Not a scientific method • not publicly observable • Nevertheless has been used as a first step in developing research questions • Purkinje

Purkinje shift (1825) • noticed that the brightness of colors changed at the end of the day as the sun was going down • day • reds and yellows appeared brighter than blues and greens • twilight • blues and greens appeared brighter than reds and yellows • duplex theory of vision • cones • rods

benefits of phenomenology • can lead us to new hypotheses and discoveries • can be useful technique to ask participants about the study after they get done. • how the felt about the study • bored? • difficult? • problem with phenomenology • not public (private experience) • difficult to know if others would have the same experience • therefore any observations would have to be verified with a scientific method.

Case studies or case history • A descriptive record of an individuals experiences and/or behaviors kept by an outside observer • Clinical psychologists often use case studies

Kazdin (1992) has argued that case studies serve five major purposes • 1) They are a source of inferences, hypotheses, and theories • The dopamine hypothesis of schizophrenia was developed from medical case studies • drugs that worked for psychosis caused Parkinson’s symptoms

2) Source for developing therapy techniques • try a new therapy and document its performance • doesn’t constitute hard evidence that it is effective • that would require control groups

3) They allow the study of rare phenomena • Luria (1968) • the mind of a mnemonist • H. M. (surgery in 1953)

4) They provide exceptions, or counter instances, to accepted ideas theories or practices • Gazziniga (1972) Split brain patients • we tend to believe that we have one unified consciousness • there is evidence that the two hemispheres represent separate consciousness that cooperate • corpus callosum • reach in bag • touch object with right hand – can tell you what it is • right hand goes to left brain • touch with left hand – can’t reply verbally, but can point to correct

5) they have persuasive and motivational value • Endel Tulving (forms of memory) • Episodic, Semantic,Procedural • H. M.

Drawbacks of case studies • When it is a rare disorder it is difficult to know if others will show similar effects • small N • When we rely on self report people may leave things out that they don’t think are important or are embarrassed about. • when they rely on retrospective data (memory) information can be inaccurate • people may not remember well • memories can be altered or reconstructed • by the way questions are asked.

Field studies • naturalistic observation • systematic observation • participant observer studies

naturalistic observation • Jane Goodall – Chimps • Gans (1962) • studied people living in slums • watched people • listened to conversations • attended meetings • found people were opposed to having the old buildings replaced

Naturalistic observation requires the researcher to be as unobtrusive as possible. • It is also primarily a qualitative method • Of course watching people in natural settings leads to high rates of external validity. • But with no manipulation of variables the internal validity is low.

Systematic observation is a more quantitative approach to naturalistic observation • the researcher creates a prearranged strategy for recording observations. • The observations are recorded using specific rules

Bakeman and Brownlee (1980) • social behavior in children • Videotaped three year olds playing together • taped for 100 minutes • observers viewed the tape and recorded behavior every 15 seconds according to the following criteria • 1) unoccupied: child is not doing anything in particular or is simply watching other children • 2) solitary play: Child plays alone with toys, but is uninterested in or affected by the activities of other children • 3) together: child is with other children bus in not occupied with any particular activity • 4) parallel play: child plays beside other children with similar toys but does not play with others • 5) group play: child plays with other children, including sharing toys, or participating in organized play activities as part of a group of children.

Type a number into the computer 1-5 every 15 seconds. • now you have quantitative data • which activity occurred the most? • what order do activities occur in? Bakeman and Brownlee noted the sequence of play activities • children rarely went from being unoccupied to group play • often went from parallel to group play • perhaps parallel play is a transitional state.

participant observer studies • This is a form of naturalistic observation in which the researched pretends to be a member of the group they are studying • Jane Goodall...and chimps might be an example. • Humphreys (1970) • befriended gay men that were meeting and having sexual encounters in public restrooms • served as a lookout • but was really collecting data • even wrote down license plate numbers, obtained addresses, disguised himself, and visited their homes to interview them. • unethical

Methodological issues for all forms of field studies • Reactivity • The presence of an observer may effect behavior • unobtrusive measures • one way mirror • hidden camera • 90 degree lens --- eyebrow arch

Reliability • the degree to which a measure is stable or consistent • inter-rater reliability • two people must score the data • if the scores are very similar you have a reliable measure • requires clear operational definitions • don’t make things too complicated • my Master’s project • 6 chambers • turning, twitching, locomotion, rearing, yawning, locomotion against wall.

Survey Research • rather than simply observing you directly question your participants about their behavior, attitudes, beliefs, and intentions • past, present, or future • two major considerations • sampling technique • construction of questionnaire

population vs. sample • Surveys are concerned with external validity. • does the data reflect how the population actually feels • to ensure that it does the sample has to be representative • convenience • simple random sampling • stratified sampling • form subgroups and sample randomly from each • Freshman, sophomores, juniors, seniors

proportionate sampling • form subgroups and sample randomly, but only as many in each group as is in actual population • freshman (31), sophomore (25), junior (14), senior (19), other (11) • cluster sampling • usually used with bigger populations • randomly select courses to be sampled • everyone in course would get the survey • better example might be school districts in Indiana. • every individual in district gets surveyed if selected.

open ended vs. closed ended questions • open ended • what do you think of parking on IPFWs campus • closed ended • How difficult is it to find a parking spot on IPFWs campus • a) easy – parking is readily available • b) somewhat easy – some days I have to look for a while • c) difficult – most days I have to look for a while • d) very difficult – Every day I spend a significant amount of time looking for a spot • likert scale • On a scale of 1-7 with 1 being very easy and 7 being nearly impossible how would you rate the ease at which you can find a parking space on IPFWs campus • 1...2...3....4...5....6....7

Nonexperimental designs