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Research Methods In Psychology Defining Psychology P Psychology is defined as the “scientific study of mental processes and behaviour in humans” (Grivas et al (2010; p 4) Behaviour Mental Processes Walking, talking, blinking... Thinking, feeling, learning... Overt – directly observable Covert – indirectly observable But how can you study something you can’t see? Steps in Psychological Research Identify the research problem Collect information and construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data Experimental Research • Key terms – Experiment – used to test the cause-effect relationship between variables under controlled conditions (p16) – Independent variable – the variable that is deliberately manipulated, changed or varied... by the experimenter in order to assess its effect. – Dependent variable – shows any effects of the independent variable; that is, it is the aspect of a participants behaviour... that is measured and is expected to change as a result of the manipulation of the IV (p17) Experimental Research Experimental Group IV is introduced... Control Group IV not introduced Is there a difference in results? Measure effect on DV Learning Activity: 1.1 REVIEW P.6 & 1.2 INVESTIGATE P1.2 Measure effect on DV Steps in Psychological Research Identify the research problem Construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data The Research Hypothesis • Key Terms – Hypothesis – a tentative and testable prediction of the relationship between two or more events or characteristics. – Operational Hypothesis – a hypothesis that states how the variables being studied will be observed and measured... • • • • OH IPOD? Operationalised IV Operationalised DV Population Prediction of relationship The Research Hypothesis A hypothesis... • Exercise reduces depression Learning Activity: INVESTIGATE 1.1 P6. An operational hypothesis... • Victorian women aged 2540 who complete 3 hours of aerobic activity a week will report fewer incidents of depression per week than women who do not complete the exercise Steps in Psychological Research Identify the research problem Construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data Extraneous and Confounding variables Extraneous Variables Confounding Variables Any variable other than the IV that does cause a change in the DV Learning Activity 1.5 Any variable other than the IV that may cause a change in the DV There’s a lot to think about when planning an experiment! Identifying unwanted variables Experimenter Effects Placebo Effect Order Effects Demand Characteristics Participant differences Artificiality Potential Variables Learning Activity 1.6, 1.7 & 1.8 Nonstandardised conditions Minimising unwanted variables Single & double-blind procedures Counterbalancing Participant selection & allocation Placebos Eliminating variables Standardised Instructions Participant Selection Population – the larger group from which the sample is selected Convenience Sampling • Selecting participants who are readily available Random Sampling Sample – a subgroup of the population used in the experiment Experimental & Control Groups Learning Activity 1.9, 1.10 & 1.11 • Every member of the population has an equal chance of being selected. Stratified Sampling • Proportions in the population match proportions in the sample. Participant Allocation Population – the larger group from which the sample is selected Sample – a subgroup of the population used in the experiment Experimental & Control Groups Learning Activity 1.12 & 1.13 Random Allocation • Every member of the sample has an equal chance of being selected for the experimental group Counterbalancing - between Group 1 Group 2 IV alcohol No IV – no alcohol No IV- no alcohol IV alcohol Counterbalancing - within Group 1 Group 2 IV No IV No IV IV No IV IV IV No IV Single and Double-blind Single-blind procedure... • ... The participants are not aware whether they are in the control or the experimental groups, so therefore unaware of the IV. Double-blind procedures... • ... The participants and the researcher/s are unaware of the conditions that participants have been exposed to. Placebos • To determine if it is the IV or a demand characteristic that causes a change in the DV, we can introduce a placebo. IV? •A placebo is a fake treatment introduced to a group so they experience the same demand characteristics as the experimental group. To determine the effect of alcohol on “having fun” at a party E2 – E1 C – no “fake” alcohol alcohol alcohol Demand Characteristics? Standardised procedures Experimental Group Control Group Identical instructions Identical Instructions Identical Procedures Identical Procedures Learning Activity 1.14 & 1.15 Experimental Research Designs Repeated Measures Design • Each participant takes part in the control group AND experimental group • Advantage – eliminates participant variables • Disadvantage – order effects Matched Participant Design • Pairs of participants, matched on some characteristic are allocated to each condition • Advantage – participant differences on important characteristic are reduced • Disadvantage – other participant variables still exist, time consuming Independent groups Design • Each participant is involved in the experimental group OR the control group • Advantage – large samples, randomly allocated can minimise participant variables • Cannot eliminate participant variables E C Learning Activity 1.16, 1.17 & 1.18 Steps in Psychological Research Identify the research problem Construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data Data Collection Techniques Qualitative Data • Information about the qualities of what is being measured... descriptions Quantitative Data • Information about the quantities of what is being studied... numbers Data Collection Techniques Objective Data • Data that is directly observable and measurable. Subjective Data • Data that is based on self-reports and more based on personal opinion. Learning Activity 1.19 Data Collection Methods Case Studies Data Collection Self-Reports •Questionnaires •Interviews Learning Activity 1.20, 1.21 & 1.22 Observational Studies Steps in Psychological Research Identify the research problem Construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data Analysing Data Descriptive statistics are used for analysing, organising, summarising and describing the results. (p64) Measures of Central Tendency Descriptive Statistics • Mean • Median • Mode Tables Graphs • Line graphs • Bar Graphs • Histograms • Frequency polygons • Pie Charts Steps in Psychological Research Identify the research problem Construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data Interpreting Data • Inferential Statistics... enable the researcher to draw inferences, or conclusions based on evidence, about the results obtained in the study – particularly regarding whether the results would also occur in the population... (p71) Sample How different do the results have to be to draw a conclusion? E Group C Group Results Results Statistical Significance A test of statistical significance is used to determine the extent to which chance has operated and whether this is an acceptable level (p72) Statistically Significant p<0.05 Not Statistically Significant p>0.05 p<0.05 means less than 5% probability the results occurred due to chance P>0.05 means greater than a 5% probability the results are due to chance What if p=0.05? Learning Activity 1.23 Conclusions and Generalisations Conclusion • A decision or judgement about what the results obtained from an investigation mean. (p73) • Extraneous variables must be considered before determining if the hypothesis is supported • A decision or judgement about how widely the findings can be applied, particularly to other members of the population... (p73) Generalisation • Sample MUST be a representative one. Learning Activity 1.24 A useful checklist... • To determine if conclusions and generalisations can be made, an experiment needs to tick all the boxes... Does the experiment use correct sampling methods? Does the experiment use a correct experimental design that minimises extraneous variables? Are the results statistically significant? Steps in Psychological Research Identify the research problem Construction of the research hypothesis Design of the method Collection of the data Analysis of the data Interpretation of the data Reporting of the data Reporting Conventions Title Abstract Introduction Method Results Discussion References Appendices Refer to “Writing an Empirical Research Report” sheet Reliability and Validity Reliability • The consistency, dependability and stability of the results. Validity • The results are an accurate measure of what they are supposed to measure. Learning Activity 1.25 & 1.26 Ethics Ethics – standards that guide individuals to identify good, desirable or acceptable conduct. (p77) Confidentiality Voluntary Participation Deception What about the use of animals in experiments? Participants Rights Withdrawal Rights Debriefing Informed Consent Learning Activity 1.27 & 1.28 Chapter Revision Good luck • True/False Quiz page 89 • Chapter 1 Test pages 9095