Psychology Statistics data report project

Method

Participants

Participants were 127 sixth- and seventh-grade students (43 boys and 84 girls) enrolled in

coeducational Brisbane Catholic Educational primary schools. Australian schools typically do

not have middle schools. The sample was evenly split according to grade level with 62 sixth-

grade students and 65 seventh-grade students. The age of students ranged from 10 to 13 years

(M = 11.42, SD = .60). Of the students sampled, 89.8% reported that they had been born in

Australia, and 87.4% reported speaking solely English at home. In Australia, Catholic Schools

typically have a low fee structure and draw students from a similar range of socioeconomic

backgrounds as the local Government schools in the same geographic areas.

Measures

Religious Preference. Respondents were asked to indicate their religious preference.

Response options included Protestant Christian (38%), Catholic Christian (14%), Other (36%),

and None (12%).

Depression. Children’s depression symptoms were measured using the Children’s

Depression Inventory (CDI), a six-item self-report measure of depressive symptomology in

children and adolescents (Kovacs, 1992). Participants respond to items indicating a depressed

state (e.g., “I am often sad”) on a 3-point Likert-type scale ranging from 1 (not at all true) to 3

(very true). Evidence of strong internal reliability of the CDI has been found in previous studies,

with Chronbach’s alphas ranging from .71 to .89 (Reynolds, 1994). Children’s self-report CDI

scores are positively correlated with parent-report measures, as well as self-report measures of

loneliness, thus supporting the validity of the measure (Carey, Faulstich, Gresham, Ruggiero, &

Enyart, 1987).

Factor analysis. An exploratory factor analysis (EFA) was conducted in order to

examine the factor structure of the six-item scale.

Only one factor had an eigenvalue greater than 1, thus suggesting a one-factor solution

according to Kaiser’s K-1 rule. The first factor explained 51.66% of the variation in scores. A

scree test was also conducted in order to determine whether the scale represented a

unidimensional construct. The scree plot was somewhat ambiguous, with the point of inflexion

being at either the second or third component, thus suggesting a one- or two-factor solution.

Next, the component matrix was examined to see whether all of the items loaded heavily onto

the first factor. All six items had loadings with absolute values over .40 on the first factor.

Reliability analysis. Next, a reliability analysis was conducted in order to determine the

internal reliability of the depression scale. This analysis produced a Chronbach’s α of .80, which

was good for psychometric purposes.

Distribution of composite scores. Finally, a composite score was created from the six-

item scale, generating a standardized (M = 0.00, SD = 1.00) depression score for each child in the

sample, ranging from -1.01 to 3.57. The resulting distribution was leptokurtic with a moderate

positive skew. Most of the respondents scored on the low end of the depression inventory with

only a few indicating high levels of depression.

Variable 3. Repeat the above process for your second composite variable.

Procedure

The students were administered the questionnaires in combined class groups, such that all

participating students from a particular school were presenting a single location in the school at

the time of the administration. The questionnaires were administered by graduate psychology

students, with classroom teachers also in attendance. The administration took place during

regular class time, and students were encouraged to work privately in answering questionnaires,

as if undertaking an exam.