Kvant Eksamen December timer med hjælpemidler. 1 Hvad er en continuous variable? Giv 2 illustrationer.

Transkript

1 Kvant Eksamen December timer med hjælpemidler 1 Hvad er en continuous variable? Giv 2 illustrationer. What is a continuous variable? Give two illustrations. 2 Hvorfor kan man bedre drage konklusioner vedrørende kausalitet med experimental research end med correlational research? Why can one better draw conclusions about causality in experimental research than in correlational research? 3 Givet de 3 værdier x = 4, 6, 8, hvad er Sum of Squared Errors og Variance? Given the three numbers x = 4, 6, 8, what is the Sum of Squared Errors and The Variance? 4 En test for Moral Sense hos børn har en standard afvigelse af 15. I en sample på 9 Moral Sense scores, hvad er Standard Error of the Mean? A test for Moral Sense in children has a standard deviation of 15. In a sample of 9 Moral Sense scores, what is the Standard Error of the Mean? 5 Hvad er inferential statistics? What are inferential statistics? 6 Hvad betyder effect size? What does effect size mean? 7 Kolmogorov-Smirnoff testen kan bruges til at teste for normalitet i en fordeling. Hvilken ulempe har testen ifølge Field?

2 The Kolmogorov-Smirnoff test can be used to test for the normality of a distribution. What disadvantage does the test have according to Field? 8 I en undersøgelse af børn finder man en korrelation på 0,4 mellem Moral Sense og Antallet af nære venner. Hvor meget varians deler de to variable, som procent? In a study of children a correlation of 0.4 is found between moral sense and number of close friends. How much variance do the two variables share, as a percentage? 9 En regressionslinje, der relater MoralSense til antal nære venner har en skæringsværdi (intercept) på 50 og en hældningskoefficient (slope) på 2. Hvad vil den forudset værdi for Moral Sense være, for et barn med 5 nære venner? A regression line relating Moral Sense to number of close friends has an intercept of 50 and a slope of 2. What would be the predicted value of a Moral Sense score for a child with 5 close friends? 10 I en undersøgelse over børn mellem 9 og 12 bliver en multiple regression gennemført med MoralSense som den afhængige (dependent) variabel og Gender (Køn), Age og CloseFriends som uafhængige (independent) variable. Resultaterne er vist i tabellen. A C Hvad er t værdien for Gender? Hvilken af de tre afhængige variable relaterer stærkest til MoralSense? Forklar dit valg. Hvad kan konkluderes fra de 3 VIF værdier? In a study of children between 9 and 12 a multiple regression is performed with MoralSense as the dependent variable and Gender, Age, and CloseFriends as the independent variables. The results are shown in the table.

3 A What is the t value for Gender? Which of the three independent variables is most strongly related to MoralSense? Explain your choice. C What can be concluded from the three VIF values? Coefficients a Model Unstandardized Coefficients Standardized Coefficients Collinearity Statistics Std. Error eta t Sig. VIF 1 (Constant) Gender ? Age CloseFriends a. Dependent Variable: MoralSense 11 To grupper af henholdsvis høj og lav angst personer gennemgår en test for psykomotor færdigheder med følgende resultater. Two groups of high and low anxious patients complete a psychomotor test with the following results. Group Statistics Score Anxiety 1.00 High 2.00 Low Std. Error N Mean Std. Deviation Mean

4 Score Equal variances assumed Equal variances not assumed Levene's Test for Equality of Variances F Sig. Independent Samples Test t df t-test for Equality of Means Sig. (2-tailed) Mean Difference Std. Error Differen 95% Confidence Interval of the Difference ce Lower Upper A Hvordan skulle Levene s test fortolkes? How should Levene s test be interpreted? Ville forskellen mellem høj og lav angst personer have været signifikant, hvis den var blevet testet en-halet (1-tailed)? Forklar dit svar. Would the difference between high and low anxious people have been significant if it had been tested one-tailed? Explain your answer. C Hvad ville gøre det legitimt at gennemføre en en-halet test? What would make it legitimate to perform a one-tailed test? D Hvad indikerer 95% Confidence Interval of the Difference? What does the 95% Confidence Interval of the Difference indicate?

5 12 I en undersøgelse over effekten af psykoterapi på højdeskræk ( vertigo ), gennemgår 21 patienter en psykoanalytisk terapi og 21 patienter gennemgår en kognitiv terapi. Deres autonome nervesystems arousal (GSR) på filmklip taget fra højder bliver målt på tre tidspunkter: før terapi, umiddelbart efter terapi, og et år efter terapi. Responserne er scoret på en skala fra 0 = lav arousal til 25 = høj arousal. In a study of the effect of psychotherapy on vertigo, 21 patients are treated with psychoanalytic therapy and 21 with cognitive therapy. Their autonomic nervous system s arousal (GSR) to film-clips taken from heights is recorded at three time-points, before therapy, immediately after therapy and one year after therapy. The responses are scored on a scale from 0 = low arousal to 25 = high arousal. Sum of Degrees of Mean Square F-ratio Squares Freedom Therapy Form 22 a b c Subjects within Groups 440 d e = error Time-Point 300 f g h Time-Point x Therapy Form 1200 i j k Time-Point x Subjects within Groups = error(time-point) 8000 l m A Giv værdierne for Give the values of a = b = c = d = e = f = g = h = i = j = k = l = m = Hvilke af effekterne er signifikant? Cf. Field s Which of the effects are significant? Cf. Field p

6 13 Giv en kort forklaring på forskellen i Variansanalyse mellem Contrasts og Post-Hoc tests Give a short explanation of the difference in Analysis of Variance between Contrasts and Post Hoc tests. 14 Forklar kort, hvad er formålet med Rotation i en Factor Analyse. Explain briefly what is the purpose of Rotation in a Factor Analysis.