THA_1_Fall

Psych 226 Fall 2021 Instructor: Karyna Pryiomka

Take-home Assignment 1

(56 points)

(due September 26th via Blackboard)

Submission notes and instructions:

1. you may complete this homework by hand and upload a picture(s) of your work to Blackboard or you may type your answers and create tables and graphs in Word or Excel and upload them to Blackboard.

2. to avoid losing points, make sure to answer each question in full.

3. read questions carefully.

4. round all answers to 4 decimal points.

Some research (ex: Rowe, 2008) in developmental psychology demonstrates that children whose parents engage in child-directed speech have better vocabulary than their peers whose parents may not engage in child-directed speech as often. To test this theory, Mia recruited a sample of 24 families with 3-year-old children. After recording each child’s biological sex and ethnicity, as well as the family’s household income, Mia randomly assigned her participants to two group. One group (n = 12) was instructed to engage in child-directed speech (Child-directed speech = Yes) for a total of at least 4 hours a day for two weeks. The other group (n= 12) served as a control (Child-directed speech = No), where parents engaged in child-directed speech for less than 4 hours a day. At the end of this two-week period, Mia measured how many new words did the children learn. Below is a hypothetical dataset for this sample. Use this dataset to complete the following tasks:

0. Identify the scale of measurement for each variable in the dataset (Note: there are 6 variables in this dataset). (12 points)

0. Construct a frequency distribution table, including proportion (round to 4 decimal points) and percent columns, for child’s biological sex. (4 points)

0. Sketch an appropriate frequency distribution graph for ethnicity. (4 points)

0. Sketch an appropriate graph showing the frequency distribution of the number of new words learned for children in the child-directed speech group (child-directed speech = Yes). In the same graph, sketch the frequency distribution of the number of new words learned for children in the control group (child-directed speech = No). Use two different colors or use a solid line for one graph and a dashed line for the other). (hint: see problems 20 and 21 in Chapter 2 and homework chapters 1 and 2) (8 points)

0. Calculate the measures of central tendency (all 3) and variability (range and sd) for the number of new words learned by children whose parents engaged in child-directed speech. (10 points)

0. Calculate the measures of central tendency (all 3) and variability (range and sd) for the number of new words learned by children whose parents did not engage in child-directed speech. (10 points)

0. Using your answers for d, e, and f, write a short paragraph comparing the two groups. Does it appear that children’s vocabulary improves when parents engage in child-directed speech for at least 4 hours a day for two weeks? Make sure to report and discuss the distribution shape, the measures of central tendency and the measures of variability for these data in your answer. (8 points)

Participant ID	Child’s biological sex	Ethnicity	Household Income in USD	Child-directed Speech	The number of new words learned
1	Male	Caucasian	95,674	Yes	7
2	Female	Latinx	75,271	Yes	6
3	Female	Asian	85,429	Yes	7
4	Female	Asian	62,823	Yes	3
5	Male	Latinx	141,644	Yes	7
6	Female	Multiracial	73,911	Yes	4
7	Male	Multiracial	144,892	Yes	7
8	Male	African American	71,458	Yes	3
9	Male	African American	63,849	Yes	6
10	Male	Latinx	140,341	Yes	4
11	Male	Asian	118,068	Yes	3
12	Male	Multiracial	93,984	Yes	5
13	Female	African American	101,722	No	6
14	Male	Caucasian	140,449	No	10
15	Male	Multiracial	57,738	No	7
16	Female	Latinx	95,039	No	10
17	Male	Latinx	72,083	No	9
18	Female	Multiracial	70,416	No	6
19	Male	African American	114,927	No	6
20	Female	Caucasian	103,270	No	6
21	Female	African American	84,880	No	9
22	Male	African American	101,978	No	9
23	Female	Latinx	147,217	No	8
24	Female	Multiracial	57,666	No	10

References

Rowe, M. L. 2008. Child-directed speech: Relation to socioeconomic status, knowledge of child development and child vocabulary skill. Journal of Child Language 35 (01), 185-205.