Essentials of Abnormal Psychology 4e 03

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.But is it an important difference? The difficulty is in thedistinction between statistical and clinical significance.dependent variable In an experimental research study, the phenomenon that ismeasured and expected to be influenced.independent variable Phenomenon that is manipulated by the experimenter in aresearch study and expected to influence the dependent variable.internal validity Extent to which the results of a research study can be attributed tothe independent variable after confounding alternative explanations have been ruledout.external validity Extent to which research study findings generalize, or apply, topeople and settings not involved in the study.Durand 3-70testability Ability of a hypothesis, for example, to be subjected to scientificscrutiny and to be accepted or rejected, a necessary condition for the hypothesis tobe useful.confound Any factor occurring in a research study that makes the resultsuninterpretable because its effects cannot be separated from those of the variablesbeing studied.control group Group of individuals in a research study who are similar to theexperimental subjects in every way but are not exposed to the treatment received bythe experimental group; their presence allows a comparison of the differentialeffects of the treatment.randomization Method for placing individuals into research groups that assureseach one of an equal chance of being assigned to any group, to eliminate anysystematic differences across groups.analog model Approach to research employing subjects who are similar to clinicalclients, allowing replication of a clinical problem under controlled conditions.generalizability Extent to which research results apply to a range of individuals notincluded in the study.[UNF.p.100-3 goes here]In the previous example, suppose we used a rating scale to note how frequentlyeach person hit himself or herself.At the beginning of the study, all the participantshit themselves an average of 10 times per day.At the end of the study, we added allthe scores on the rating scales and found that the treated group received lower scoresthan the untreated group and the results were statistically significant.Is this newtreatment something we should recommend for all people who hit themselves?Closer examination of the results leads to concern about the size of the effect.Let sDurand 3-71say that when you look at the people who were rated as improved you find they stillhit themselves about six times per day.Even though the frequency is lower, they arestill hurting themselves.Some hit themselves just a few times but produce seriouscuts, bruises, and contusions.This suggests that your statistically significant resultsmay not be clinically significant, that is, important to the people who hurt themselves.The distinction would be particularly important if there were another treatment thatdid not reduce the incidence of self-hitting so much but reduced the severity of theblows, causing less harm.Fortunately, concern for the clinical significance of results has led researchers todevelop statistical methods that address not just that groups are different but howlarge these differences are, or effect size.Calculating the actual statistical measuresinvolves fairly sophisticated procedures that take into account how much each treatedand untreated person in a research study improves or worsens (Grissom & Kim,2001).In other words, instead of just looking at the results of the group as a whole,individual differences are considered as well.Some researchers have used moresubjective ways of determining whether truly important change has resulted fromtreatment.The late behavioral scientist Montrose Wolf (1978) advocated theassessment of what he called social validity.This technique involves obtaining inputfrom the person being treated and from significant others about the importance of thechanges that have occurred.In our example, we might ask employers and familymembers if they thought the treatment led to truly important reductions in self-injurious behavior.If the effect of the treatment is large enough to impress thosedirectly involved, the treatment effect is clinically significant.Statistical techniques ofmeasuring effect size and assessing subjective judgments of change will let us betterevaluate the results of our treatments.Durand 3-72The Average ClientToo often we look at results from studies and make generalizations about the group,ignoring individual differences.Kiesler (1966) labeled the tendency to see allparticipants as one homogeneous group the patient uniformity myth.Comparinggroups according to their mean scores ( Group A improved by 50% over Group B )hides important differences in individual reactions to our interventions.The patient uniformity myth leads researchers to make inaccurate generalizationsabout disorders and their treatments.To continue with our previous example, it wouldnot be surprising if a researcher studying the treatment of self-injurious behaviorconcluded that the experimental treatment was a good approach.Yet suppose wefound that, although some participants improved with treatment, others got worse.Such differences would be averaged out in the analysis of the group as a whole, butfor the person whose head banging increased with the experimental treatment, itwould make little difference that on the average people improved.Because peoplediffer in such ways as age, cognitive abilities, gender, and history of treatment, asimple group comparison may be misleading.Practitioners who deal with all types ofdisorders understand the heterogeneity of their clients and therefore do not knowwhether treatments that are statistically significant will be effective for a givenindividual.In our discussions of various disorders, we return to this issue.Concept Check 3.3In each of the statements provided, fill in the blanks with one of the following:hypothesis, dependent variable, independent variable, internal validity, externalvalidity, or confound.1.In a treatment study, the introduction of the treatment to the participants isreferred to as the _______ variable.Durand 3-732.After the treatment study was completed you found that many of the people inthe control group received treatment outside of the study.This is called a_______.3.A researcher s guess about what her study might find is labeled the _______.4.Scores on a depression scale improved for a treatment group after therapy.Thechange in these scores would be referred to as a change in the _______ variable.5.A relative lack of confounds in a study would indicate good validity, whereasgood generalizability of the results would be called good _______ validity.Types of Research MethodsCompare and contrast different research designs, including the types of questionsthat are appropriate and inappropriate for each.Behavioral scientists use several different forms of research when studying the causesof behavior.We now examine individual case studies, correlational research,experimental research, and single-case experimental studies.Studying Individual CasesConsider the following scenario: A psychologist thinks she has discovered a newdisorder.She has observed several men who seem to have similar characteristics.Allcomplain of a specific sleep disorder: falling asleep at work [ Pobierz całość w formacie PDF ]

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