Study and sheet notes

De opdracht voor de werkgroep bevatte de volgende vragen. 

1. Describe the terms of reliabilty and validity. 

• Reliability = the extent to which a measurement is free from random measurement errors. This means that the scores are independent of time, place and environment.
• Construct validity = the extent to which the instrument (operationalization) succeeds in measuring the construct and thus fits the conceptual definition.
• Internal validity = the extent to which the research method can eliminate alternative explanations for an effect/relationship.
• External validity = the extent to which the research results can be generalized to other populations, settings and times.
• Statistical validity = the extent to which the results of a statistical analysis are accurate and well- founded.

2. What are the conditions for being able to speak of a causal relationship?

• Two or more variables should be related
• The cause should precede the outcome over time
• No other explanations may be possible

3. How can a sample be used to to make inferences about a population?
Inferential statistics use probability theory to formulate general statements based on samples about the populations from which these samples were taken.

4. What are the assumptions of multiple regression?

• Independent observations
• Dependent variable should be continuous.
• Independent variable should be continuous or dichotomous. A categorical predictor can be changed into several dichotomous variables (dummy’s).
• Linear relationship between predictors and dependent variable.
• Absence of outliers (in X, Y and XY-space)
• Absence of multicollinearity
• Homoscedasticity
• Normality distributed residuals

In de rest van de werkgroep is het volgende artikel besproken:

Kanazawa, S. (2012). Intelligence, birth order, and family size. Personality and Social Psychology Bulletin, 38(9), 1157-1164. https://doi.org/10.1177/0146167212445911

6. Describe the three different explanation sgiven in the introduction for the relationship found between intelligence and birth order. Note. Do not discuss the revised confluence model. 

1. Confluence model: The average intelligence of children decreases with an increasing birth order. The higher the birth order, the less a family is a cognitively stimulating environment.
2. Resource dilution model: The average intelligence of children decreases with an increasing birth order. This is because parents have only a limited number of resources, energy and attention to distribute. The higher the birth order, the less resources the family still has available.
3. Admixture hypothesis: The relationship between intelligence and birth order is a methodological artefact. The relationship between intelligence and birth order is only found because parents with lower intelligence often have more children.

7. What are the population and sample in the article? Describe the participants that are participating. In your description also explain exactly what the different sweeps mean conceptually.

A ‘population’ of British respondents is used. Participants were all babies born in Great Britain on March 3-9, 1958. These participants were measured over a longer period of time, during which data were collected at various moments (sweeps). This study uses data collected on sweep 0 (age 0), sweep 1 (age 7), sweep

Study and sheet notes

De eerste vragen gaan over het artikel:

Brunell, A.B., Fisher, T.D. (2014). Using the bogus pipeline to investigate grandiose narcissism.Journal of Experimental Social Psychology, 55, 37-42. https://doi.org/10.1016/j.jesp.2014.05.015

1. What is the research question of Brunell and Fisher (2014)?
To what extent are grandiose narcissism and other narcissism-related constructs sensitive to bias in reporting?

2. In the article, an experimental manipulation is used.
a. Please explain, in your own words,what a bogus pipeline is.

The bogus pipeline is a technique used by social psychologists to reduce socially desirable answers. Participants are linked to a device that the researchers tell them is a lie detector. As a result, participants have the feeling that they are being checked to see whether they are responding truthfully. It is assumed that this will actually motivate participants to answer truthfully.

b. Describe, in your own words, what the differences are between the experimental conditions in this study.

The idea behind this is that by using the bogus pipeline technique, amongst other things, the measurement of social constructs becomes more valid. Giving socially desirable answers is a systematic error that affects validity.
Bogus pipeline condition: Participants were told that they would be linked to a lie detector during the experiment. Participants completed the questionnaires while they were linked to the bogus pipeline.
Anonymous condition: Participants in this condition were not linked to a lie detector. Participants filled in the questionnaires in a private setting. 
Exposure threat condition: Participants in this condition were not linked to a lie detector. Participants completed the questionnaires, with a survey assistant in the room. This research assistant informed the participants that he/she would pick up the questionnaire afterwards. In all conditions, the participants submitted the questionnaires in a closed box.

De volgende vragen van de voorbereidende opdracht gaan over replicatie, assumpties en type I fouten. 

Replication Explanation  

Assumptions ANOVA

• Homogeneity of variances
• Independence of observations
• Absence of outliers
• Normal distribution
• Measurement level

Assumptions ANCOVA

• Measurement level of the covariate should be continuous
• Independence of the covariate and the treatment effect (no statistical requirement)
• Homogeneity of regression coefficients

Type I error

Study and sheet notes

Het eerste deel van de vragen gaat over het artikel van Firk et al. (2018) met als referentie:

Firk, C., Konrad, K, Herpertz-Dahlmann, B., Scharke, W., & Dahmen, B. (2018). Cognitive development in children of adolescent mothers: The impact of socioeconomic risk and maternal sensitivity. Infant Behavior and Development, 50, 238-246. https://doi.org/10.1016/j.infbeh.2018.02.002

1. What is the research question of Firk et al. (2018)?

What are the differences in children’s cognitive development between children of adolescent and adult mothers in their first two years of life? Are these differences between children of adolescent and adult mothers mediated by maternal parenting qualities?

2. What is the hypothes is of the researchers with regard to this research question?

No clear hypothesis is mentioned, but Firk et al. do repeat what they want to investigate: They want to test the hypothesis whether maternal socioeconomic problems have a direct effect on child outcome or whether this effect is mediated by maternal sensitivity.

3. Describe in your own words which groups the researchers want to compare. How did the researchers select these samples?

Mother-child dyads were recruited within a project on adolescent parenting in cooperation with the local youth welfare system, obstetric clinics, midwife practices and pediatrician practices. Adolescent mothers were all < 21 years, adult mothers were all > 25 years. It is unclear how the samples were actually selected, but it appears that all dyads that wanted to participate and met the inclusion criteria, were included in the study.

4. In the results section, study the first mediation model that the researchers analyze. What is in this model the independent variable (X), the dependent variable (Y) and the mediator (M)?

X = Maternal age
Y = Cognitive development
M = Maternal sensitivity

5. For model 1, use the values included in the text and in the notes of Figure 2, to fill in the table below. For each effect, note (a) the lower and upper boundaries of the confidence interval, (b) whether the value 0 falls between these boundaries, and (c) whether this effect is significant.

6. What is the conclusion of Firk et al. (2018)? Is this in line with their hypothesis?

When controlling for maternal IQ, children of adolescent mothers showed lower cognitive skills than children of adult mothers. In the current study, this difference emerged when children were between 18 and 24 months of age. In contrast to children of adult mothers, whose age-standardized scores were comparable at all time-points, age-standardized scores for children of adolescent mothers decreased from T2 to T3.

When controlling for maternal IQ, Firk et al.

Work group: studypath SHOP

In this work group we discussed the article of Escartin et al (2011). The article can be found by Escartín, J., Salin, D., & Rodríguez-Carbaillera, Á. (2011). Conceptualizations of workplace bullying. Gendered rather than gender neutral? Journal of Personnel Psychology, 10, 157-165. https://doi.org/10.1027/1866-5888/a000048. 

The researchers investigate what the significance of gender is for how employees define bullying and how severe they rate different forms of bullying to be. They form four hypotheses: 

1. Hypothesis 1: Women are more likely to include person-related forms of bullying (emotional abuse and social isolation) in their definitions of bullying.
2. Hypothesis 2: Men are more likely to include work-related forms of bullying (the other categories) in their definitions of bullying.
3. Hypothesis 3: Women rate the severity of bullying behavior as more severe than men do.
4. Hypothesis 4: Gender differences in perceptions of severity vary across the different forms of bullying.

Hypothesis 1 and 2 are tested in study 1 and hypothesis 3 and 4 are tested in study 2. 

The researchers do not specifically mention the population to which they want to generalize the results of the research. However, they do state that 'One should always be cautious when generalizing findings from one specific country or region'. It therefore seems likely that they want to generalize to the general working population, but that they do realize that they are dealing with a specific research group. 

The sample of study 1 is a convenience sample of 246 employees (154 women, 92 men). Participants were recruited in two different ways: (1) one set of participants (109 employees) were recruited at workshops on the prevention of workplace bullying held by one of the authors and (2) a second set of participants (137 employees) were recruited via administrative services. The sample of study 2 is also a convenience sample of employees. Participants were recruited via email from four different organizations, 39.9% of the questionnaires were actually filled in (300 employees; 191 women, 109 men).

The research procedure of study 1 is not completely described. All we know is that as part of the study participants were asked to think about their own definition of bullying. How participants were asked to do this was not mentioned (questionnaire on paper, digital, interview?). It is also unclear when the data was collected (this is particularly interesting for the participants who were recruited at the workshops on the prevention of workplace bullying, did they answer the questions during the workshops? At which moment?). We do know that the data has been collected (partly) qualitatively, but was processed quantitatively. In study 2, employees from various branches of four organizations were sent a questionnaire by e-mail. In this questionnaire, all participants were asked questions about background information and they had to assess the severity of different types of bullying.

They performed two statistical analyses: logistic regression and hierarchical regression analyses. The researchers report nothing about the assumptions of the analyses. However, in both studies they did not include age as a predictor in the analyses because this variable