Psychology Unit Four
Revision Lecture
19/10/10
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 test
Extraneous Variables
 Teacher
 learning environment
 deb. Ball night before topic test
Variables
Confounding 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 group
The 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 group
The 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 Sampling
Sampling 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 Designs
Repeated measures
An 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-participants
An 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 DESIGNS
Independent groups
An experiment where participants are randomly allocated to one
of two separate groups.
Adv. Reduces order/practice/fatigue effects
Disadv. Doesn’t control participant variables.
Counterbalancing
A 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 Effect
Any 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 values
The 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.
Statistical significance
The 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.
Probability
Means 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
Inferential Statistics
Mathematical 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
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
I read a wonderful quote in a book called "Ladies First" by actress and
rapper Queen Latifah. She said her brother encouraged her to do lots
of different things. Queen wrote, "He was adventurous and taught
me that the more you try, the more surface area you create in which
to succeed..." (http://www.geocities.com/gidi2/doors.html)
Check out the following useful websites for further information about
revision and study!
http://www.geocities.com/gidi2/mrsm.html
http://www.google.com/Top/Kids_and_Teens/School_Time/Homework_Help/
http://chiron.valdosta.edu/whuitt/col/cogsys/sq4r.html
Study Techniques
What about trying one or a number of the following?
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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)
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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.