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Published byJanel Parker Modified over 9 years ago
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THE RESEARCH METHODS USED IN PSYCHOLOGY RESEARCH ENTERPRISE IN PSYCHOLOGY
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GOALS OF THE SCIENTIFIC ENTERPRISE There are 3 interrelated goals 1: Measurement and description—how do we measure the phenomenon 2: Understanding and prediction—hypothesis, variables (measurable conditions—controlled or observed) 3: Application and control—theories (bring understanding from description and generates new predictions)
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STEPS IN A SCIENTIFIC INVESTIGATION 1: Formulate a testable hypothesis—variables must be defined Operational definition describes actions or operations that will be used to measure or control a variable
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STEPS 2: Select research method and design the study Depends on nature of the question Experiments, case studies, surveys, naturalistic observation, etc…
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STEPS 3: Collect the data How data is collected depends on what is being investigated
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STEPS 4: Analyze data and draw conclusions Statistics are used to analyze and determine the validity of the hypotheses
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STEPS 5: Report the findings Findings usually submitted to a journal: periodical that publishes technical and scholarly material
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ADVANTAGES OF THE SCIENTIFIC APPROACH 1: It is clear and precise 2: Intolerant of error---findings are reviewed by other skeptical researchers
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EXPERIMENTAL RESEARCH
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EXPERIMENT Def: a research method where a variable is manipulated under carefully controlled conditions and observes changes in that variable
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INDEPENDENT AND DEPENDENT VARIABLES Ind. Variable: one that is changed to see its impact on another variable (controlled or manipulated) Dep. Variable: one that is affected by manipulation of the ind. variable
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EXPERIMENTAL AND CONTROL GROUPS --Experimental Group: subjects who receive special treatment in regard to the ind. variable --Control Group: do not receive special treatment --Both groups must be similar, except in treatment
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EXTRANEOUS VARIABLES Def: any variables other than ind. variable that seem to influence the dep. variable in a specific study Even if groups are alike there are smaller differences that could affect outcome
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EXTRANEOUS VARIABLES Confounding of variables: when 2 variables are linked together in a way that makes it difficult to sort out their specific traits Makes it difficult to see which variable is affecting the outcome
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HOW TO PREVENT EXTRANEOUS VARIABLES Random assignment: when subjects have an equal chance of being assigned to any group or condition in the study
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VARIATIONS IN DESIGNING EXPERIMENTS Sometimes it is good to use only one group Instead you create control conditions and experimental conditions
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VARIATIONS CONTINUED Manipulate more than one ind. variable in a single experiment Allows researchers to see if two variables interact
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VARIATIONS CONTINUED Use more than one dependent variable in a single study Helps form a more complete picture
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ADVANTAGES OF EXPERIMENTAL RESEARCH Allows conclusions about cause and effect relationships btwn variables Creates precise control Helps avoid extraneous variables
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DISADVANTAGES OF EXPERIMENTAL RESEARCH Experiments are artificial Experimental method can not be used in some instances (ethics) Sometimes it is hard to manipulate variables
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PERMITS RESEARCHERS TO DESCRIBE PATTERNS OF BEHAVIOR AND DISCOVER LINKS BETWEEN VARIABLES DESCRIPTIVE/ CORRELATIONAL
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NATURALISTIC OBSERVATION Def: researcher observes w/o interfering directly Strength: experiments are less artificial Weakness: hard to remain unobtrusive
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CASE STUDIES Def: in-depth investigation of an individual subject Includes: interviews, observation, testing Good w/psych disorders Problem: highly subjective
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SURVEYS Def: use of questionnaires or interviews to gather info. about specific aspects of a subject’s behavior Use to gather info. hard to observe Easy to gather from a large sample
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ADVANTAGES OF DESCRIPTIVE/CORRELATIONAL RESEARCH Broadens scope of what can be studied Covers some of what can’t w/experimental research Cannot control events Cannot demonstrate that 2 variables are casually related
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STATISTICS: USE OF MATHEMATICS TO ORGANIZE, SUMMARIZE, AND INTERPRET NUMERICAL DATA STATISTICS AND RESEARCH
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DESCRIPTIVE STATISTICS Used to organize and summarize data Include measure of central tendency, measures of variability, and the coefficient of correlation
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CENTRAL TENDENCY 3 measures: 1: Median: score that falls in the center of the distribution of scores 2: Mean: avg. of scores (most useful) 3: Mode: most frequent score
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VARIABILITY Def: how much the scores in a distribution vary from each other and from the mean Standard of deviation: an index of the amount of variability in a set of data Large variability = large standard of deviation Small variability = small s.o.d.
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CORRELATION Def: when 2 variables are related to each other Correlation coefficient: numerical index of the degree of relationship btwn 2 variables—indicates direction of correlation and the strength of the relationship
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POSITIVE/NEGATIVE CORRELATION Positive(+): variables co-vary in the same direction (Ex.: increased study time = increased test score) Negative(-): variables co-vary in opposite direction (Ex.: increased absences = decreased test scores)
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STRENGTH OF CORRELATION Size of coefficient indicates strength Coefficient varies btwn 0 and +1.00 (pos.); 0 and - 1.00 (neg) Closer to zero, the weaker the relationship
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CORRELATION AND CAUSATION Correlation does NOT mean causation
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INFERENTIAL STATISTICS Def: used to interpret data and draw conclusions Did chance play a factor? Statistical significance: exists when the probability that the observed findings are due to chance is very low (5 chances in 100)
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EVALUATING RESEARCH
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REPLICATION Def: repetition of a study To test results Can change results entirely
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META-ANALYSIS Def: combines statistical results of many studies of the same question, giving an estimate of the size and consistency of a variable’s effect Allows to test the generalizability of findings across people, places, and times and variations in procedure in a precise and objective way
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SAMPLING Sample: collection of subjects being observed in a study Population: group from which the sample is taken
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SAMPLING BIAS Def: exists when a sample is not representative of the population from which it was drawn
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PLACEBO EFFECT Def: occurs when participant’s expectations lead them to experience some change even though they receive empty, fake, or ineffectual treatment
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DISTORTIONS IN SELF-REPORT DATA Questionnaires, inventories, interviews have flaws Social desirability bias: tendency to give socially approved answers to questions about oneself
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DISTORTIONS Response set: tendency to respond to questions in a particular way that is unrelated to the content of the questions
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EXPERIMENTER BIAS Def: when researcher’s expectations about the outcome of a study influence the results obtained
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DOUBLE-BLIND PROCEDURE Def: research strategy in which neither subjects nor experimenters know which subjects are in the experimental or control groups
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DO THE ENDS JUSTIFY THE MEANS? ETHICS
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QUESTION OF DECEPTION Deceiving in order to observe specific situations Proponents: “white lies”, not harmful to participants, benefits worth it Critics: it is lying, may diminish trust, may produce distress in subjects
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ANIMAL RESEARCH Some treatments are unacceptable for humans Only 7-8% of all psychological studies involve animals Very controversial
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