Presentation on theme: "Research in Psychology Chapter Two"— Presentation transcript:
1 Research in Psychology Chapter Two AP Psychology
2 Thinking Critically About Psychology What am I being asked to believe or accept?What evidence is available to support the assertion?Are there alternative ways of interpreting the evidence?What additional evidence would help to evaluate the alternatives?What conclusions are most reasonable?
3 Reliability and Validity Evidence addressing a hypothesis should be judged in terms of reliability and validity.
4 TheoriesA theory is an integrated set of statements designed to account for and predict ways of controlling certain phenomena.They are tentative explanations that must be subjected to scientific evaluation.They are constantly being formulated, evaluated, reformulated, and sometimes abandoned based on research results.
5 Goals of Psychological Research To describe the phenomenonTo make accurate predictionsTo demonstrate some control over the variablesTo explain the phenomenon with confidence
7 Naturalistic Observation Feature: The process of watching without interfering as behavior occurs in the natural environmentStrengths: Provides descriptive data about behavior presumably uncontaminated by outside influences.Pitfalls: Observer bias and participant self-consciousness can distort results
8 Case StudiesFeature: Intensive examination of the behavior and mental processes associated with a specific person, group or situation.Strengths: Provide detailed descriptive analysis of new, complex, or rare phenomenon.Pitfalls: May not provide representative picture of phenomena.
9 SurveysFeature: Standard set of questions asked of a large number of participants – asks people about their behavior, attitudes, beliefs, and opinionsStrengths: Gather large amounts of descriptive data relatively quickly and inexpensively.Pitfalls: Sampling errors, poorly phrased questions, and response biases can distort results.
10 Correlational Studies Feature: Examine the relationships between research variables.Strengths: Can test predictions, evaluate theories, and suggest new hypotheses.Pitfalls: Cannot infer causal relationships between variables.
11 CorrelationCorrelation – the degree to which one variable is related to another
12 Correlation Coefficients Correlation Coefficient – a statistic, r, that summarizes the strength and direction of a relationship between two variablesIndicates directionof relationship(positive or negative)Correlationcoefficientr = +.37Indicates strengthof relationship(0.00 to 1.00)Strong CorrelationModerate CorrelationWeak Correlation
13 Illusory CorrelationThe perception of a relationship where none existsMisinterpretation of random sequences
14 ExperimentsFeature: Manipulation of an independent variable and measurement of its effects on a dependent variable.Strengths: Can establish a cause-effect relationship between independent and dependent variables.Pitfalls: Confounding variables may prevent valid conclusions.
16 Figure 2.1: A Simple Two-Group Experiment Independent Variable: Whether or not one received the EMDR treatment.Dependent Variable: Anxiety level.
17 Sources for Confounding Variables Random VariablesImportance of random assignmentParticipants’ ExpectationsPlacebo effectExperimenter BiasOften minimized through the use of a double-blind design
18 ResearchBasic research- describe and understand behavior without immediate concern for practical use.Applied research- scientific studies to solve problems of everyday life.
19 Selecting Human Participants for Research The sampling procedures used can:Affect the research results.Limit the meaning of the resultsSampling – the process of selecting participants for research
20 Representative Samples A group of research participants whose characteristics fairly reflect the characteristics of the population from which they were selectedIf psychologists want to make scientific statements about the behavior and mental processes of any large group, they must use a representative sample of participants
21 Random vs. Biased Samples Random - A group of research participants selected from a population whose members all had an equal chance of being chosenBiased – A group of research participants selected who did not have an equal chance of being chosen
22 Convenience SamplesPopulations that are conveniently available to the researcherResearcher must check age, gender, ethnicity, and other characteristics of participants
23 Statistical Analysis of Research Results Descriptive Statistics - #s that describe a set of research dataMeasures of Central TendencyMeasures of VariabilityCorrelation CoefficientsInferential Statistics – a set of mathematical procedures that help researchers infer what their data mean
24 Cross-Sectional Research A study of various ages at one point in time.Positives: can gather information about the effect in each age group
25 Ethics Ethical considerations: Reviewed by a board in academic institutionsCodes put out by APAObtain informed consent from all subjectsProtect subjects from harm and discomfortTreat all data confidentiallyExplain the experiment and results to subjects afterward.
26 Animal CareReviewed by a committee IACUC (institutional animal care and use committee)Will periodically visit animal colonies to ensure proper care
27 Measures of Central Tendency Mean – averageMedian – halfway pointMode – occurs most frequently
28 Measures of Variability Range – difference between highest and lowest valuesStandard Deviation (SD) – average distance between each score and the mean of the data set
29 Table 2.4: A Set of Pretreatment Anxiety Ratings