Psychology Unit Four

Revision Lecture19/10/10

Leonie Fryer

Hypothesis (‘ses’ plural)• Hypothesis - prediction about the outcome of research

• Operational hypothesis – Operational – says how the D.V. will be measured.– Directional - it states the relationship between the I.V. and

the D.V.– Population - states who they are.– States the I.V.

– Null hypothesis - statement that the I.V. will have no effect on the D.V.Researcher aims to reject the Null Hypothesis.

Variables

• Research aims to test predictions about the relationship between variables (I.V. and D.V.)

• Independent Variable I.V. is the factor controlled by the researcher. = “cause”

• Dependent Variable D.V. factor that is measured (usually behaviour). D.V. is affected by the I.V. = “effect”

Variables

I.V. “cause”Extra Revision(after school classes)

D.V. “effect”Exam performance

(improved)

Variables

Extraneous Variable any uncontrolled factor that can affect the D.V.

I.V. Extra revision (after school classes)D.V. Performance on topic testExtraneous Variables Teacher learning environment deb. Ball night before topic test

VariablesConfounding Variable an uncontrolled factor that

varies in the same way as the I.V. You can’t determine whether change in the D.V. is due to the I.V. or the confounding variable. No conclusions can be drawn.

I.V. Extra revision (after school classes)D.V. Performance on topic test• Confounding Variable - Deb. Ball night before topic

test

Control and Experimental Groups

Control groupThe control group in an experiment is the group that is NOT exposed to the I.V., does NOT receive the treatment.A control group is there to provide a basis for comparison with the experimental group.

Experimental groupThe experimental group in an experiment receives the ‘treatment’ and IS exposed to the I.V.

Research Methods

Descriptive statistics: summarise, organise and describe. e.g. calculating average (mean), median and mode in a set of data.cannot be used to determine whether results are statistically significant.

Inferential statistics:based on mathematical calculations and show the likelihood of a chance result. e.g. t test.can be used to determine whether results are statistically significant. can be used to draw conclusions.

Participant SamplingSampling is the procedure used to gather participants for

research.Sample – a subset of the population.Random Sampling - A technique where every participant has an

equal opportunity of being selected.Adv. It is likely that the sample will be more representative of

the original population.Stratified Random Sampling - A technique where the population

is divided into groups or strata FIRST and then the participants are randomly selected from each of these groups/strata. (e.g. gender, age, ethnic background)

Adv. It is likely that the sample will be more representative and in the correct proportions as the original population.

Participant Allocation

Allocation refers to the technique used to put participants into groups during research. Statistically, the best way to allocate people to groups in research is to randomly assign them. So each person has an equal chance of being in either the control or experimental group.

Ethical principles• Professional Conduct (Do No Harm) – Researcher’s

responsibility to the participant to ensure that NO physical or psychological harm occurs.

• Informed consent – Participants must have knowledge of nature and purpose of research. Consent must be documented.

• Withdrawal rights – Participants must be free to leave the research at any time. Also withdraw their results.

• Debriefed – Researcher must inform the participants about the nature, results and conclusion after the study is finished.

• Voluntary Participation – Participants must not be coerced or forced to take part in research.

• Confidentiality – Participants have the right to privacy, so personal details, confidential data and results cannot be published.

Ethical principles

• Beneficence – Research must maximize benefits to participants and society and participants must be protected from harm.

• Justice – Any benefit or disadvantage experienced during research must be the same for all participants. Participants should be representative of the population.

• Integrity – The researcher is committed to the study because of the potential benefits to the understanding of human behaviour.

Research DesignsRepeated measuresAn experiment where the same group of participants makes up

both the experimental and the control groups.Adv. Participant effects minimized (same people both grps)Disadv. Practice or order or fatigue effects can occur.

Matched-participantsAn experiment where participants are ‘paired’ up on similar

characteristics relevant to the research.Adv. Controls for order, practice or fatigue effects.Disadv. Requires more participants. May not control participant

variables/differences.

RESEARCH DESIGNSIndependent groups An experiment where participants are randomly allocated to one

of two separate groups.Adv. Reduces order/practice/fatigue effectsDisadv. Doesn’t control participant variables.

CounterbalancingA technique where half the participants in a study are exposed

to the experimental condition first and half are exposed to control condition first. Then they swap over.

Adv. Controls for order/practice/fatigue effect.

Placebo EffectAny change in the behaviour of participants in research ‘caused’

by a placebo (belief) and NOT the I.V. There is a measurable difference in the behaviour of participants who took the placebo and those who didn’t.

Placebo is a ‘fake’ pill or injection.

So if participants take a placebo pill; they may behave differently because they ‘think’ the pill has had an effect (belief).

Single blind

A technique used during an experiment where the participants do not know whether they are in the experimental or control group.Participants are “blind” to who gets the I.V.

Adv. To control for placebo effects.

Double blind

A technique used during an experiment where the participants AND the experimenter do not know who is in the experimental or control groups.

Participants and experimenter are both “blind” to who gets the I.V.

Adv. To control for both placebo effect and experimenter effect.

Analysis – P valuesThe Null Hypothesis can be rejected if the results are statistically

significant.“P” = probability of gaining a result by chance. Inferential

statistics allow us to calculate whether result is due to chance or the I.V.

Critical level for claiming that a result is statistically significant – P ≤ 0.05.

P ≤ 0.05 means that the risk of a chance result is 5 or less in 100, or 95% sure the result is due to the I.V.

e.g. P ≤ 0.01 is statistically significant (99% sure result is due to I.V.).

You can reject Null Hypothesis. P ≥ 0.05 is NOT statistically significant (risk of chance result is greater than 5 in 100). Cannot reject Null Hypothesis.

Inferential StatisticsMathematical procedures used to judge whether (a) the research results would occur by chance (b) results from the sample used would also occur in the population

Statistical significanceThe term used to indicate when the difference between the control and experimental groups is a real difference (statistically)

The critical level required for results to be called statistically significant is the P<0.05 level.

A result is statistically significant if it would happen by chance only 5% of the time or less.

ProbabilityMeans the likelihood of a result occurring

by chance

P < 0.05 means the probability of a chance result is less than or equal to 5%, or 5: 100 or 1 in 20

Probability

A statistically significant result means that the research results are due to the Independent Variable

Statistically significant results mean that (a) there is a causal relationship between IV and DV and (b) results can be generalised to the population

Which of the following are statistically significant?

P>0.05

P<0.01

P>0.001

Revision & Study Techniques

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Study Techniques

What about trying one or a number of the following?

• Draw a mind/concept map (Venn diagram, fishbone graphic) or a picture or cartoon.

• Write your own True/False, multiple-choice or short answer question.• Teach someone else about the concept/topic – you have to understand and

remember it to be able to do this!• Do a few exam questions and correct them.• Test someone else, then ask them test you. Try questions that apply the

knowledge, not just declarative questions.• SQ3R: - Survey -- Read chapter outlines, chapter headings, recaps, objectives, etc.

Question -- Formulate questions you believe will be addressed in reading. Read -- Read material quickly, carefully, actively; try to answer previously formulated questions. Recite -- Explain aloud to yourself or another person what you have read; use study guide; answer questions at end of chapter. Review -- Go back over what you have learned; use study guide; reread recaps, reviews, or end of chapter summaries.

END OF YEAR EXAMINATION

Format:- Consists of 44 multiple choice questions and 16-18 short answer questions. It will cover the Memory, Learning and Research Methods. Multiple choice 44 questions, 44 marks. Short Answer Section 16-18 questions 46 marks.

• Date:- Thursday 4th November 2010• Time:- 9.00am to 10.45am (15 minutes reading time, 1 hour 30 minutes writing time)

BEFORE THE EXAM• Don’t panic whatever happens, you DO know the topics in the course.• Get up at least 2 hours before your examination.• Go for a 10 minute jog or a 15 minute brisk walk.• Ensure that your pens, pencils are ready and in your bag.• Get ready early, have breakfast.• Look over your notes.• Arrive early be there 10 minutes prior to the start.• Relax!

IN THE EXAM

• Use the reading time to go over all of the examination paper, carefully.

• Information in the multiple choice questions will be useful for the short answer section.

• Move through all the questions, do the ones you can do easily.

• Allow time to come back to all missed questions.• Divide your writing time evenly between the m/c questions

and the short answer.• GOOD LUCK!

REVISION AND EXAMINATION PREPARATION - tips

• Use the handouts for each area of study to guide your revision; the VCAA dots points are the ones you’ll be asked about in the exam.

• Use the study skills handout to plan your revision leading up to the examination.

• Use Checkpoints. Complete all the M/C and S/A questions for Unit 4.• Use your textbook. Have you completed all the key questions? Learning

Activities? Multiple choice questions? Short Answer questions at end of the chapters?

• Do complete AT LEAST a couple of full practice exams on your own, including corrections.