Friday, July 13, 2012

REGISTRATION FOR RDA IIB

Notice Regarding Registration for Research Design & Analysis IIB:

If you have registered for RDA IIB, or are considering doing so, please note the following:

1.     The course code for RDA IIB is PSYC2006. It is only offered on the full-time schedule in the B-slot.

2.     If you have achieved a mark of at least 60% for RDA IIA (either PSYC2005 or PSYC2012), you may register for RDA IIB. However, please note that the marks for RDA IIA were somewhat higher on average than they have been in previous years, and we would not recommend registering for RDA IIB unless you have achieved a mark of at least 65% for RDA IIA.

3.     There are no other requirements to register for RDA IIB, but students should bear in mind that the course is not compulsory for the major in Psychology and does not have to be taken as part of a degree with a major in Psychology. It is however recommended for those students who are seriously considering postgraduate studies in Psychology, and is extremely useful in terms of extending practical understanding of how to conduct research.

4.     Students who have not yet registered for RDA IIB and would like to do so now will need to collect an amendment of registration form from their Faculty, fill in the course code “PSYC2006” under “courses to be added”, bring this to the Department of Psychology for a signature of approval, and then return the form to Faculty. Students must follow up with Faculty to ensure their registration is changed accordingly within the week provided for amendments, i.e. all changes to registration must be finalised by Friday 20th July.

5.      Any student who is currently registered for PSYC2006 (RDA IIB) but who did not obtain a mark of 60% or more for RDA IIA must deregister from the course within the first week of the second semester i.e. by Friday 20th July. To de-register, students should collect an amendment of registration form from their Faculty, fill in the course code “PSYC2006” under “courses to be dropped”, bring this to the Department of Psychology for a signature of approval, and then return the form to Faculty. Students must follow up with Faculty to ensure their registration is changed accordingly within the week provided for amendments.

If you have any queries regarding the above information, please do not hesitate to contact me.

Thanks,
Kevin

Monday, July 9, 2012

Link to RDA final marks

PSYC 2005 provsional marks may be accessed at:

https://docs.google.com/spreadsheet/ccc?key=0Am7uz368AQc4dFpCaW1CXzEwRXd4bzFtTUtQcmdOZ2c

RDA IIA MARKS ARE AVAILABLE

The department has released provisional marks for all Psychology courses. These have been put up on the noticeboards on the mezzanine level between the ground and first floor of Umthombo Building

Sunday, July 1, 2012

Notice re: examination marks

The Department is hoping to publish provisional june exam marks during the last week of the break (after 9 July 2012).

A notice will be placed on the course blog as soon as the marks are released

Thanks

Kevin

Saturday, June 16, 2012

Item discrimination/item analysis

Please ignore all questions in past papers on item analysis and item discrimination. You have not covered this in the course this year GOOD LUCK FOR MONDAY!

Wednesday, June 13, 2012

RESEARCH DESIGN REVISION LECTURE: MAY/JUNE 2011 PAPER


MAY/JUNE EXAMINATION 2011

SECTION A

Research Design – Dr Sumaya Laher & Ms Nicky Israel


Question 1

a)    Quantitative

Tests a hypothesis that the researcher begins with; concepts in the form of distinct variables; measures standardized and systematically created before data collection; data in the form of numbers; focus on objective facts and causal and deductive theory; procedures are standard and replication is possible, analysis conducted using statistics etc…

b)    Protection and welfare of participant; informed consent; use of deception; debriefing; right to withdraw/voluntary nature participation; confidentiality and/or anonymity; differential treatment of the two groups etc…


Question 2
a)    Is a 14-session cognitive behavioural program effective in improving intrinsic mottion?

b)    IV = Cognitive behavioural program
c)    Operationalisation of the IV = participants divided into groups, one group received the intervention, the other did not  
d)    DV = Motivation
e)    Working definition of the DV = “Intrinsic motivation is defined as engaging in activity purely for the pleasure and satisfaction derived from that activity while extrinsic motivation is defined as performing an activity in order to obtain a separate outcome
f)     Operationalisation of the DV = Sport Motivation Scale (SMS)
g)    Measurement validity. Any sensible argument re whether the operationalisation of the DV (i.e. use of the SMS) was appropriate for the study or not

Question 3
a)    IV (intervention) manipulated, given to one group and withheld from the other; Experimental and control group, one receiving treatment, one not; Random assignment; True experimental design;Pre-test, post-test control group design
b)    Advantage: causality
Disadvantage: artificiality and generalizability

d)    Advantage: can be administered to large numbers of people, time and cost efficient, provide a type of 'anonymity', yield valuable descriptive information about broad trends
Disadvantage: application from one population / demographic area to another, low rate of questionnaire – return, ambiguous replies, depends on the truthfulness of the subject


 Question 4
a)    Temporal precedence - IV manipulated
Covariation - control and experimental group
Non-spuriousness – random assignment but can never be established completely
Therefore, researcher was justified in making causal conclusions to a high degree
i) Diffusion – could/not impact the study as group attended separate sessions but were from the same community and may have had contact etc…
ii) Selection Bias – could not impact the study as there was random assignment
b)    Testing is a threat because pretest and posttest are the same test or any sensible variation thereof
Can be countered by post-test only or Solomon four groups or parallel versions of the test – any one sensible suggestion
Differential attrition could be a threat because passage indicates individuals dropping out and different numbers dropping out from the two groups or any sensible variation thereof
Can be countered by having sacrifice groups or similar suggestion

Question 5
a)    Sample = Sixty-five students from the University of the Witwatersrand (48 male, 17 female) who enrolled in and completed an introductory cricket course as part of their physical education course
b)    Sampling technique = non-probability, convenience sample, volunteers
c)    Population = characteristics of the sample compared to those of the population  
Ecological = degree to which it is appropriate to generalize from one context to another
d)    Any critical point with reference to ecological or population validity
e)    Replication, triangulation, choose random sample, more representative sample, larger sample or any other two sensible suggestions

Question 6
a)    Independent t-tests are appropriate because they indicate whether there is a significant difference between the mean scores of two independent groups – in this case the experimental and control group would be independent / any reference to parametric assumptions being met
b)    Statistical conclusion validity
c)    Qualitative paradigm
With any sensible justification – focus groups, subjective, interactive method, data in the form of words, extract themes, greater depth of info


SECTION B

Psychometrics – Ms Nicky Israel


Question 1
a)    Embody the knowledge and expertise of others; developed more objectively and scrutinized more carefully than other forms of data collection; represent a collective understanding of a phenomenon; assign numbers to characteristics and allow for the use of statistics; allow for standards of performance to be compared etc…
b)    Closed-ended, Likert-type scale (from Does not correspond at all to Corresponds exactly)
C)    Objective scoring rules: scoring rules guarantee the same outcome
d)    Criterion-based: interpreted by comparison against a set standard

Question 2
a)    Consistency of test scores, extent to which scores affected by random error, poor reliability suggests poor validity etc...
b)    Test-retest reliability
The range indicates moderate to high stability and motivation over three to six months would not necessarily change that much so these estimates would not be unexpected
c)    Internal consistency reliability
Kuder-Richardson 20, Spearman Brown
d)    Internal consistency estimates are affected by the number of items in the scale and the average inter-item correlation. Each subscale measures a different aspect of motivation, and therefore one would not necessarily expect items from the one scale to relate that well to items from the other scale, which would affect the estimate. By calculating internal consistency for each scale, one can assume that all the items in the subscale should relate – 2 marks

Question 3
a)    No, reliability indicates whether the test provides consistent measurement – if the measurement is not consistent, it cannot then assess what it claims or purports to assess (validity) because it has not been shown to assess anything at all
b)    Construct validity – relationship between test scores and measures of other, un/related constructs and behaviours
Convergent validity - expect relationships between scores and scores on the Motivation for Physical Activities Measure-Revised and measures of dedication
Convergent validity – expect relationship between scores and absenteeism from training
c)    Construct validity - relationship between test scores and measures of other, un/related constructs and behaviours
Discriminant validity – do not expect relationship between gender or race and test scores
d)    Criterion-related validity – relationship between test scores and an independent outcome measure
Concurrent validity – assessed in a pre-selected, restricted group  
e)    Content validity/Face validity

Question 4

a)    Bias = systematic error
Fairness= value judgement re decisions/way test used
b)    Fairness – relates to how the test was used
c)    Similar strong correlations with related constructs observed for all groups; similar weak correlations for unrelated constructs observed for all groups; predictions follow same pattern for all groups
d)    Any four sensible points related to bias and the SMS
e)    Any two sensible points related to cultural bias and the exemplar items

Question 6
a)    Inheritance of policies and practices; attitudes to testing; bias; new legislation; multiculturalism/linguilism; resources etc…
b)    Dynamic assessment; computerized/ adaptive testing; interviews etc…

Monday, June 11, 2012

PSYC2005 (RDA IIA) Exam I (Statistics) October/November 2011

PSYC2005 (RDA IIA) Exam I (Statistics) October/November 2011   Question 1 a)      Correlation (use formula for Pearson’s r). The answer is r = + 0.1229 b)      Very weak, positive linear relationship – although yearmark and exam mark move in the same direction, they are only very weakly related.   Question 2 i)        Comparison of two groups (librarians and designers) – no reason to link a specific librarian to a specific designer therefore two independent groups. Assume parametric therefore run a t-test for two independent samples. ii)       Null hypothesis would be H0: Mu 1 = Mu 2 (or Mu p = Mu q) iii)     Alternate hypothesis would be H1: Mu 1 not equal to Mu 2 (or Mu p not equal to Mu 2) because told to test for a difference iv)     Alpha = 0.05 v)      n is 10 for group 1 and 10 for group 2, the degree of freedom is therefore 10 plus 10 minus 2 which is 18.  The test statistic would be t18 = 1.4574. vi)     The critical areas would be 0.025 in each tail; the corresponding critical values from t-tables would be 2.101 and -2.101. vii)   1.4574 is outside the critical areas therefore Fail to Reject H0 at alpha = 0.05. viii)  There is insufficient evidence at the 0.05 level of significance to believe that there is a significant difference between the librarians and designers in mean time to recognize the word.   Question 3 Sampling distribution: Mean IQ (x-bar) is distributed normally with a mean of 100 and a variance of 16-squared over 36 (standard deviation of 16 over the square root of 36). The probability that the average IQ is at least 102 (i.e. greater than 102) is 0.2266 (z =  0.75).   Question 4 i)        Comparison of three groups, parametric therefore ANOVA ii)       Null hypothesis would be H0: Mu 1 equal to Mu 2 = Mu 3 (all the means are equal) iii)     Alternate hypothesis would be H1: at least one pair of means not equal iv)     Alpha equals 0.05 v)      SS error  = 511.46, k = 3, df between = 2, N = 30, df error = 27, df total = 29, MS between = 90.535, MS error = 18.943, test statistic is F (2; 27) = 4.7793 vi)     The critical area would be 0.05 in the right tail; the corresponding critical value from F-tables would be 3.35.  vii)   4.7793 is inside the critical area therefore Reject H0 at alpha = 0.05. viii)  There is sufficient evidence at the 0.05 level of significance to believe that there is a significant difference between the time to complete the task between at least two of the conditions   Question 5 i)        Association between two nominal variables (gender – male/ female and driving speed – below limit, at limit, above limit) therefore Chi-squared test of association  ii)       Null hypothesis would be H0: there is no relationship between gender and driving speed iii)     Alternate hypothesis would be H1: there is a relationship between gender and driving speed  iv)     Alpha equals 0.05 v)      The test statistic would be Chi-squared 2 = 35.796 (please refer to hand out for steps). vi)     The critical area would be 0.05 in the right tail but please use the non-directional row on the table; the corresponding critical value from Chi-squared -tables would be 5.99.  vii)   35.796 is inside the critical area therefore Reject H0 at alpha = 0.05. viii)  There is sufficient evidence at the 0.05 level of significance to believe that there is a relationship between gender and driving speed   Question 6   a)      IV = dominance = nominal; DV = span in centimetres = ratio. Comparison of two linked measurements (groups) therefore matched. DV is at least interval, no other information given re other parametric assumptions (although the sample size is 15 which is too small for Central Limit Theorem to apply and could indicate that the data might not be normally distributed). If assume the other parametric assumptions, including normality, are met, could run a parametric matched pairs t-test; if assume the other assumptions, for example, normality, are not met, would run a Wilcoxan’s MPSR test.  b)      IV = background risk factors composite score – at least ordinal (probably interval); DV = substance abuse score – at least ordinal (probably interval). Assessing relationship therefore use correlation/ regression. c)       IV = TV programme type = nominal; DV = serotonin level  measurement = interval (could argue ratio). Comparison of four groups, DV is at least interval, no other information re parametric assumptions is given. Assuming these are met, could run a parametric ANOVA, if not met could run a Kruskal-Wallis. d)      IV = reading ability = nominal; DV = IQ = interval. One group/sample compared to a population where the standard deviation/ variance for the population is known, therefore use a z-test e)      IV = TV viewership = nominal; DV = annual income = nominal. Relationship between two nominal variables therefore use a Chi-squared test of association.     Question 7 a)      False, zero represents the absence of measurement on a ratio scale. b)      False, a statistic can take on different values and is therefore not fixed. c)       False, the dependent variable in a regression line can be accurately estimated using any value that is within the range of recorded values for the independent variable. Outside this range is extrapolation. d)      True, sample size is n and the standard deviation of the sampling distribution is sigma over the square root of n. As n gets larger, one would divide by a larger number and the answer would get smaller. e)      False, the null hypothesis assumes the status quo i.e. no change and the alternate hypothesis proposes what the experimenter would like to prove.  

REVISION LECTURES - STATISTICS 11 JUNE, RD/PSYCHOMETRICS 14 JUNE

RDA IIA REVISION LECTURE
Statistics

Monday, 11th June, 11h00-14h00* in SHB 5 (Senate House Basement 5)

*This revision lecture is OPTIONAL. We will try to finish as early as possible, depending on questions and discussion.

NB: Please bring all handouts you have received in tutorials and tables with 

Please prepare the following:
a)         OCTOBER/NOVEMBER EXAM 2011 – PSYC2012: EXAM 1 (Statistics) (pp. 27-31 in Tutorial Pack II)
b)    Any additional examples from any of the exams that you would like to go over for Statistics and/or any questions you have for this section.

If you are not able to attend this revision session, you are welcome to come and consult with the lecturers during their exam consultation times and/or please organise to get notes from a friend.


RDA IIA REVISION LECTURE
Research Design & Psychometrics

Thursday, 14th June, 9h00-12h00* in SHB 5 (Senate House Basement 5)

*This revision lecture is OPTIONAL. We will try to finish as early as possible, depending on questions and discussion.

Please prepare the following:
a)         MAY/JUNE EXAM 2011 – PSYC2005: EXAM 2 (Research Design & Psychometrics) (pp. 23-27 in Tutorial Pack II)
b)    Any additional examples from any of the exams that you would like to go over for Research Design or Psychometrics and/or any questions you have about either section.

If you are not able to attend this revision session, you are welcome to come and consult with the lecturers during their exam consultation times and/or please organise to get notes from a friend.

Wednesday, June 6, 2012

Link to access RDA IIA yearmarks

Please click on the link below to access your marks:

https://docs.google.com/spreadsheet/ccc?key=0Am7uz368AQc4dGI0YzlTNEdwVGplUTFCQmZhbExaa2c

RDA YEARMARK ANNOUNCEMENT

Research Design & Analysis IIA (PSYC2005)

Important Notice about Year Marks:


Please note that as a result of a technical error, the year marks posted on the notice board earlier this week were incorrect in a small number of cases. These errors have been corrected, and the year marks now posted should be correct. However, please check your marks carefully, and if you have a good reason to believe that the marks reflected for you are still incorrect, then please contact me as soon as possible!

Thanks,
Kevin

Tuesday, June 5, 2012

Nicky Israel revised consultation times

Nicky Israel Revised Consultation Times: June Exams and July break   Wednesday 6th June:                           13h00 – 15h00 Thursday 7th June:                               10h45 – 13h00 Tuesday 12th June:                              8h00 – 9h30; 12h30 – 15h00   Thursday 14th June:                            12h30 – 14h00 Friday 15th June:                                  9h00 – 11h00 For short queries, you are welcome to email: Nicky.Israel@wits.ac.za   Please note that except for these times, I will only be available by appointment during the exam period and the break. If I am not in my office during these times, or you need to reach me outside of these times, please email me at: Nicky.Israel@wits.ac.za Alternatively, please contact me on 717-4557 or leave a note with your contact details (preferably including a landline number) either under my door or in my pigeonhole in U211 (Psychology Main Office).  

Monday, June 4, 2012

RDA YEARMARKS

Please note: Yearmarks have been posted on the RDA noticeboard. All queries should be directed to Dr. Kevin Whitehead ( Kevin.whitehead@ wits.ac.za). Some marks are still pending as these were the deferred tests

Monday, May 28, 2012

Herbert Hove and Elsabe Smit Consult times - June 2012

RDA IIA (PSYC2005) JUNE EXAM CONSULTATION
Herbert Hove, CB 134
Friday 8 June 2012 10:00 – 12:30, 13:00 – 15:00
Monday 11 June 2012 11:00 – 13:30, 14:00 – 15:30
Tuesday 12 June 2012 10:00 – 12:30, 13:00 – 15:00
Elsabé Smit, CB 131
Monday 4 June 2012 14:00 – 15:00
Wednesday 6 June 2012 10:00 – 13:00
Thursday 7 June 2012 10:00 – 13:00
Friday 8 June 2012 10:00 – 13:00
Monday 11 June 2012 13:00 – 15:30
Tuesday 12 June 2012 10:00 – 12:30, 13:00 – 15:00

Saturday, May 26, 2012

Nicky Israel - consultation times

Nicky Israel

Consultation times: June Exams and July break


Monday 28th March: 9h30 – 11h00

Monday 4th June: 9h00 – 12h00

Wednesday 6th June: 13h00 – 15h00

Thursday 7th June: 10h45 – 13h00

Tuesday 12th June: 9h00 – 12h00

Thursday 14th June: 12h30 – 14h00

Friday 15th June: 9h00 – 11h00

For short queries, you are welcome to email: Nicky.Israel@wits.ac.za

Please note that except for these times, I will only be available by appointment during the exam period and the break. If I am not in my office during these times, or you need to reach me outside of these times, please email me at: Nicky.Israel@wits.ac.za

Alternatively, please contact me on 717-4557 or leave a note with your contact details (preferably including a landline number) either under my door or in my pigeonhole in U211 (Psychology Main Office).

Sunday, May 20, 2012

Internal validity class exercises


It is widely recognized that the growth of the Internet in recent years has led to people of all ages having unprecedented access to both hard-core pornography and ‘soft’ erotic materials. Over a similar time period, there has also been a massive increase in levels of infection of sexually-transmitted diseases, not only HIV/AIDS, but also other diseases such as syphilis and gonorrhea. Researchers contend that these two phenomena are linked, and further that the increasing availability of ‘soft’ erotic material in particular actually promotes irresponsible sexual behaviour. In an attempt to establish whether this is in fact the case, this study attempted to explore the effects of exposure to ‘soft’ erotic material on attitudes towards responsible sexual behaviour.



Forty-four female (mean age = 24.7 years) and thirty-one male (mean age = 26.2 years) postgraduate students at the University of the Witwatersrand volunteered to participate in the study. Subjects were told that they were participants in a study on information processing and that they would have the opportunity to discuss the study and their results upon completion of the data collection phase of the study.



Subjects were randomly assigned to one of two groups. Individuals in both groups completed the Sexual Attitudes Survey A. Group 1 was then shown an Internet-based short movie entitled ‘Reckless Abandon in the Western Cape’ (restricted to no under-18’s and classified as ‘soft’ erotic material). During the same time-frame, Group 2 was shown an Internet-based ‘neutral’ movie entitled ‘The Mating of South African Birds’, which described the courtship behaviour of various species of birds indigenous to the Western Cape. Once they had finished watching the movies, both groups were asked to complete the Sexual Attitudes Survey B (an alternate but equivalent scale to Survey A).



Mean scores obtained by both groups on the Sexual Attitudes Survey are presented in Table 1.




Survey A
Survey B
Group 1 (n = 39)
92.8
85.7
Group 2 (n = 31)
93.3
92.2



Statistical analysis of results indicated a statistically significant difference in attitudes for individuals in Group 1 but no statistically significant difference for individuals in Group 2. Based on this the researchers concluded that exposure to ‘soft’ erotic material negatively affected attitudes towards responsible sexual behaviour.



1.    What is the research question underpinning this study?

Does exposure to ‘soft’ erotic material have an effect on attitudes towards responsible sexual behavior?



2.    Briefly state the hypothesis being tested here.

Exposure to ‘soft’ erotic material does have an effect on attitudes towards responsible sexual behavior



3.    What is the independent variable?

Exposure to ‘soft’ erotic material



4.    How was the independent variable operationalised?

Group 1 was then shown an Internet-based short movie entitled ‘Reckless Abandon in the Western Cape’ (restricted to no under-18’s and classified as ‘soft’ erotic material). During the same time-frame, Group 2 was shown an Internet-based ‘neutral’ movie entitled ‘The Mating of South African Birds’, which described the courtship behaviour of various species of birds indigenous to the Western Cape.



5.    What is the dependent variable?

Attitudes towards responsible sexual behavior



6.    How was the dependent variable operationalised?

Individuals in both groups completed the Sexual Attitudes Survey A before the manipulation and the Sexual Attitudes Survey B after the manipulation. Thus attitudes towards responsible sexual behavior was operationalized using the Sexual Attitudes Survey – Forms A and B



7.    Which group is the experimental group?

Group 1 – They were shown an Internet-based short movie entitled ‘Reckless Abandon in the Western Cape’ (restricted to no under-18’s and classified as ‘soft’ erotic material).



8.    Which group is the control group?

Group 2 – They were shown an Internet-based ‘neutral’ movie entitled ‘The Mating of South African Birds’, which described the courtship behaviour of various species of birds indigenous to the Western Cape.





9.    What type of research design has the researcher employed? Substantiate your answer.

Quantitative. True-experimental because control and experimental group present, IV was manipulated (the film that contained ‘soft’ erotic material), there was random assignment. Pretest-postest control group design because both groups were prested and post tested.



10. Discuss one advantage and one disadvantage of using this research design

Advantage - Pretest establishes baseline on attitudes

Disadvantage – Prestest introduces possibility of carryover effects



11. Which research design would you have suggested had you been commissioned to do the research initially? Substantiate your answer

Solomon four group design since this overcomes pretest effects



12. Based on the results of the study, the researchers’ clearly made causal        conclusions. Discuss whether or not these conclusions are appropriate by making reference to notions of causality.

Conclusions justified since covariation criterion met because experimental and control group present, temporal precedence met because the IV was manipulated, non-spuriousness met to an extent because random assignment present



13. Identify and discuss five possible threats to the internal validity of this study.

History – it is possible for something to occur in the context for one group but for the other

Diffusion – all are postgraduate students on campus. There is the possibility for the experimental group to find out what the control group is receiving and vice versa.

Differential Attrition – it is evident from group sizes before and after that people dropped out of the study

Hawthorne effects – students could respond in a particular way simply because they are taking part in a study not in response to the manipulation

Good subject effects - students could respond in a socially desirable way because they are being altruistic subjects

Interactional experimenter effects – students can be responding to biological or psychosocial characteristics of experimenter rather than to the manipulation



14. Suggest three ways in which you think the internal validity of this study could have been improved.

History – have standardized conditions for both groups

Diffusion – make sure students have no opportunity to meet or conduct study over shorter time period.

Differential Attrition – use quasi controls

Have random sampling.

Get bigger sample sizes

Use triangulation

Use interviews or focus groups to supplement qualitative data





SELF STUDY:



1.   The best description of internal validity deals with the questions of:

whether the observed outcomes of an experiment are the result of the experiment itself rather than the result of some extraneous factor



2.   When a researcher is concerned that the results which she observes after an experiment might have occurred because of the composition of the group itself rather than because of the experimental treatment, with which of the major threats to internal validity is she most obviously concerned?

Selection Bias



3.   If a researcher is concerned that it might have been some extraneous event that occurred while the experiment was going on rather than the experimental treatment itself which caused an observed outcome, with which of the following threats to internal validity is he most obviously concerned?

History



4.   A primary school teacher finds that her Grade One pupils are having trouble with their basic mathematics concepts. She therefore tries a new teaching method and plans to evaluate it at the end of the year to see if it has made an improvement. She will consider her program successful if the children have mastered a large number of skills at the end of the year which they had not mastered at the beginning of the year. Which of the following is the most obvious threat to the evaluation of the program?

Maturation



5.   Each year a primary school teacher provides a lesson in his physical education class on ‘The Rules of International Soccer (Football).’ In 2010, since it was a Soccer World Cup year, he decided to revise and upgrade the lesson. He initiated his lesson to coincide with the start of the televised portions of the World Cup. In the final exam, he asked his usual ten questions about International soccer. He found that the 2010 students scored substantially higher than the students from the previous three years had on the same questions. He concluded that his new program had been effective. Which of the following is the most obvious threat to the internal validity of the study?

History



6.   Changes in subject’s behaviour which occur through the realisation that they are the subjects in a scientific study are called:

Hawthorne effects




7.   The use of recorded laughter to accompany television and radio comedy shows is a well known and widespread practice. The authors chose to investigate the effects of audience laughter on individuals’ responses to humour. Forty undergraduate psychology students at the University of Aberdeen were placed in one of two conditions:

     a)    an experimental condition, in which participants listened alone to a radio comedy program, 'Arnold Brown and Company ' (BBC Radio, 1990) with the natural laughter of the audience present on the track, and

     b)    a control condition that listened to the same recording without the laughter.



     After listening to the tape, the participants were presented with a questionnaire to assess their humour response. The questionnaire consisted of 7-point rating scales assessing funniness and enjoyability. Statistical analyses revealed the following:

    

     Funniness   -  F (1,36) = 8.33, p = 0.007 **

     Enjoyment  -  F (1,36) = 7.89, p = 0.008 **

     ** significant at 0.01 level of significance



     Those participants who listened with laughter present gave significantly higher   

      ratings of the funniness and enjoyability of the recording.



1.    State the hypothesis being investigated in this study.

The presence of audience laughter is associated with individuals’ responses to humour



2.    What is the independent variable?

Presence/ansence of audience laughter



3.    What is the dependant variable and how has it been operationalised?

responses to humour – was operationalized using a questionnaire consisting of 7-point rating scales assessing funniness and enjoyability.



4.    What type of research design has the researcher employed? Substantiate your answer.

Quantitative. Quasi-experimental because control and experimental group present, IV was manipulated (the presence or absence of audience laughter), there was no random assignment. Postest only nonequivalent control group design because both groups were only post tested.



5.    Discuss one advantage and one disadvantage of using this research design

Advantage – no pretest so no carryover but also disadvantage no baseline

Disadvantage – no random assignment so no non-spuriousness. Also no other controls for extraneous variables



6.    Which research design would you have suggested had you been commissioned to do the research initially? Substantiate your answer

Pretest-posttest control group design or Solomon four group design (with justification) will be correct



7.    Would the lecturer be justified in stating a causal hypothesis for this study? Substantiate your answer by making reference to notions of causality

No. Conclusions not justified since covariation criterion met because experimental and control group present, temporal precedence met because the IV was manipulated, but non-spuriousness not met because no random assignment present. They also did nothing else to control for extraneous variables.





8.    Identify and briefly discuss five possible threats to the internal validity of this study.

History – it is possible for something to occur in the context for one group but for the other

Diffusion – all are postgraduate students on campus. There is the possibility for the experimental group to find out what the control group is receiving and vice versa.

Selection bias – no random assignment to control or experimental groups

Hawthorne effects – students could respond in a particular way simply because they are taking part in a study not in response to the manipulation

Good subject effects - students could respond in a socially desirable way because they are being altruistic subjects

Interactional experimenter effects – students can be responding to biological or psychosocial characteristics of experimenter rather than to the manipulation



9.    Suggest three ways in which this study may be improved.

History – have standardized conditions for both groups

Diffusion – make sure students have no opportunity to meet or conduct study over shorter time period.

Selection bias – use random assignment, use quasi controls

Have random sampling.

Get bigger sample sizes

Use triangulation

Use interviews or focus groups to supplement qualitative data