PYC3704/202/2/2017
Tutorial Letter 202/2/2017
Psychological Research
PYC3704
Semester 2
Department of Psychology
Feedback to assignment 02
BARCODE
, Dear Student
This study letter contains answers and explanations of the correct options for each question in
Assignment 02. Information on the format of the exam is provided in Tutorial Letter 102. That letter also
contains additional exercises, with answers, which you can use to test yourself in preparing for the exam.
The questions in the two assignments and those at the end of each topic in the Study Guide for
PYC3704 should be used as part of your preparation for the exam. We suggest that you try to do the
questions from the Guide and the assignments without looking up the answers. In this way you will see
which questions you can answer, and which ones you cannot answer. This will help you to identify the
difficult questions, and force you to rethink the reasons for the answers. Pay special attention to the
explanations we provide, since this will give you an indication of the weak spots in your own
understanding of the material in the Study Guide. Do not attempt to memorise the questions and their
answers. Rather try to understand the explanations for the correct option in each question. If you did
not receive pass marks for the assignments, you will have to work much harder if you want to pass the
exam.
Feedback to Assignment 02 for Semester 2
For your convenience, each question is given followed by the appropriate answer and an
explanation of the correct response. Work your way systematically through these, comparing it with
your own answer. Even if you chose the correct option, you may find that the explanations we give are
useful. Try to understand the explanations. Many of the items measure insight, not just factual
knowledge.
Question 1
Why do we calculate a test statistic?
1. To determine whether or not we can accept that the null hypothesis is true
2. To determine how far the observed measurements deviate from what we may expect by chance
3. To get a measurement by which we can calculate the level of significance
4. To determine whether or not we can reject the alternative hypothesis
Answer: Option 2 is correct.
Calculating the test statistic is the first step in a process of comparing the observed data with what may
be expected by chance (that is, if in fact the null hypothesis is true and any effects observed in the
sample of data are due to random errors).
Option 1 is not really appropriate because the emphasis is wrong here. The test statistic is calculated to
determine whether the effect is large enough to reject the null hypothesis and not to try to accept it. For
the same reason, Option 4 is not really correct (rejecting the alternative hypothesis would follow only as
a consequence of the null hypothesis not being rejected). The level of significance is not calculated but
chosen, so Option 3 is false.
2
Tutorial Letter 202/2/2017
Psychological Research
PYC3704
Semester 2
Department of Psychology
Feedback to assignment 02
BARCODE
, Dear Student
This study letter contains answers and explanations of the correct options for each question in
Assignment 02. Information on the format of the exam is provided in Tutorial Letter 102. That letter also
contains additional exercises, with answers, which you can use to test yourself in preparing for the exam.
The questions in the two assignments and those at the end of each topic in the Study Guide for
PYC3704 should be used as part of your preparation for the exam. We suggest that you try to do the
questions from the Guide and the assignments without looking up the answers. In this way you will see
which questions you can answer, and which ones you cannot answer. This will help you to identify the
difficult questions, and force you to rethink the reasons for the answers. Pay special attention to the
explanations we provide, since this will give you an indication of the weak spots in your own
understanding of the material in the Study Guide. Do not attempt to memorise the questions and their
answers. Rather try to understand the explanations for the correct option in each question. If you did
not receive pass marks for the assignments, you will have to work much harder if you want to pass the
exam.
Feedback to Assignment 02 for Semester 2
For your convenience, each question is given followed by the appropriate answer and an
explanation of the correct response. Work your way systematically through these, comparing it with
your own answer. Even if you chose the correct option, you may find that the explanations we give are
useful. Try to understand the explanations. Many of the items measure insight, not just factual
knowledge.
Question 1
Why do we calculate a test statistic?
1. To determine whether or not we can accept that the null hypothesis is true
2. To determine how far the observed measurements deviate from what we may expect by chance
3. To get a measurement by which we can calculate the level of significance
4. To determine whether or not we can reject the alternative hypothesis
Answer: Option 2 is correct.
Calculating the test statistic is the first step in a process of comparing the observed data with what may
be expected by chance (that is, if in fact the null hypothesis is true and any effects observed in the
sample of data are due to random errors).
Option 1 is not really appropriate because the emphasis is wrong here. The test statistic is calculated to
determine whether the effect is large enough to reject the null hypothesis and not to try to accept it. For
the same reason, Option 4 is not really correct (rejecting the alternative hypothesis would follow only as
a consequence of the null hypothesis not being rejected). The level of significance is not calculated but
chosen, so Option 3 is false.
2
