Presentation on theme: "IB Psychology Internal Assessment Higher Level 20% of final grade"— Presentation transcript:
1 IB Psychology Internal Assessment Higher Level 20% of final grade Standard Level25% of final grade
2 The TaskReplicate an experiment that manipulates an Independent VariableWrite a report conforming to IB guidelines
3 IA Differences between SL and HL Weighting: 25%Replicate a published experimental study;Characteristics of SL simple experimental study:Limited in scopeInvolves the manipulation of only one independent variableInvolves the measurement of only one dependent variableRequires the use and interpretation of the descriptive statisticsDoes NOT require the use of inferential statistics ;State the aim of the study.Weighting: 20%HL students:may undertake a replication or a modification of a published experimental study;Are required to undertake more extensive background research related to their simple experimental study; 3 studies!!!State an operationalized experimental hypothesis;State an operationalized null hypothesis;Apply inferential statistical test to their data and interpret the result of the test.
5 Step 1: Choosing an experiment to replicate Guidelines:Ensure that the study has an IV that you can manipulate (not gender/age/culture) e.g. verbs, background noise.Your experiment should be relatively easy to replicate, cognitive experiments concerning memory are best suited to the Internal Assessment.You must clearly justify and operationalize your hypotheses.
6 Step 1: Choosing an experiment to replicate Guidelines:You can not deceive, harm, or ask your participants to eat or drink any substancesYou are not expected to conduct a ‘perfect’ experimentYou are not allowed to replicate experiments about/using: conformity & obedience, animal research, placebo, ingestion, deprivation, young children, quasi experiments, questionnaires.
7 Step 2: Locating Sources Try to locate a copy of the original experiment on the internetFind at least 3 other related studies – RESEARCH!Analyze how all of these studies relate to your experiment – look at research design, findings etcAvoid too many internet sources. No Wikipedia!!!
8 Student AdviceDo not underestimate the amount of time required to complete the IADo not choose a study that is too obscureScientific writing is “way harder” than you thinkThink about the best time to hold your experiment so that students will turn upTime management is the key!!!
9 Step 3 Modifying the Research Design You will have to modify the original experimentSamplingReduce the number of variablesSimplify the DVUse a different statistical test to determine significance
10 Step 3 Modifying the Research Design cont’ Independent measures design Vs. repeated measures design . (Be able to justify this in your report)Independent measures is usually best as you don’t have to undertake counterbalancing to avoid the test-retest confounding variable
11 Step 4 Obtaining your sample of participants Student body will be your target populationIt is best to select an opportunity sample but you will have to justify why you did this. i.e. easier, Ppts more willingAn ideal sample is 50 students giving you two groups of 25.If you have some no-shows you will still have 20 per group
12 Step 4 Obtaining your sample of participants Signed informed consent forms must be obtained (You will provide a copy of the consent form in your appendix)Students younger than 16 will require parental consentYou must keep all forms and ensure the confidentially of dataYou must collect relevant bio-data from the participants e.g. age, first language etc. You will report any relevant characteristicsYou must randomly assign participants to your groups!
13 Step 5 Ensuring ControlThe two groups in your experiment should be treated exactly the same except for the IVAll instructions to the groups should be scripted to ensure they are identicalAll other conditions should be identical as far as possible; Room, time of day etc. Control for extraneous variables!Note any inadvertent differences in treatment and discuss this in your report
14 Step 6 Ethical Considerations Remind participants that they are free to leave the experiment at any timeDebriefing: All participants must be informed of the results of your experiment
15 Step 7 Analyzing the Data – Descriptive Stats Use appropriate descriptive statistics (one measure of central tendency and one measure of dispersion)Present your data in both words and tabular form.
16 Step 8 Analyzing the Data – Inferential Stats Use non-parametric statistical tests of significance (Mann Whitney U-test)Your small sample size prohibits parametric tests like the t-test.Best to calculate your test yourself but double check with online sitesRaw data and calculations should be included in the appendix
17 Which Inferential Test? HL only!! Level of measurementAppropriate test for independent samplesAppropriate test for repeated measuresNominal(Categories, frequency)Chi-squared (X2 test)Ordinal, Interval or RatioMann-Whitney U testWilcoxon signed ranks test
18 Writing Your Report You MUST follow the IB guidelines. Common omissions: no abstract; data not displayed in three ways i.e. words, tables and graphs; sources not cited, no Works Sited page; no appendices (sample informed consent form, raw data, statistical test calculations, scripted instructions)You must write like a social scientist. Avoid the 1st person “Basically I did this, then I did…..”