PSYC 354
BIOL 102 EXAM 1 STUDY GUIDE
All exam questions are taken from Modules/Weeks 1 and 2, Nolan and Heinzen. There is no
SPSS content. The study guide is organized by topic.
Populations and Samples:
1. Define what a sample is and identify the sample in a research scenario. For example, in a
study with 15 student participants who have a mean SAT score of 678, what is the
sample? Sample is a set of observations drawn from population of interest. The sample is
15 students
2. What is the letter used to identify the sample size? In other words, the number of
participants in a study is represented by what letter? Letter “n”
3. Explain the difference between a sample and a population. Why are samples used more
often than populations in research? Samples are used most often because reserachers are
rarely able to study evry person in a a population.
Descriptive and Inferential Statistics:
1. Define a descriptive statistic and give an example. Be able to identify a descriptive
statistic in a research scenario. For example, in a study with 15 student participants who
have a mean SAT score of 678, what is the descriptive statistic?
Answer: organizes, summarizes, and communicates agroup of numerical observations.
Mean SAT score of 678
2. Define inferential statistics and explain how they are used by researchers.
Answer: inferential statitics use sample data to make general estimates about the larger
population
3. Understand that the main difference between these two types of statistics (descriptive vs.
inferential) is that one describes and summarizes the data set while the other uses the data
to draw conclusions about a larger population.
Variables and Levels of Measurement:
1. Define a variable.
A variable is any observation of a physical, attitudinal, or behavioral characteristic that
can take on different values.
2. Define a value or score. What is the relationship between a variable and a value? In this
list, which is the variable and which is the value? a. IQ score b. 120
3. What is the difference between a discrete variable and a continuous variable? Can you
give an example of each one and identify why one is discrete while the other is
continuous?
A discrete observation can take on only specific values (e.g., whole numbers); no
other values can exist between these numbers. For example, if we measured the
number of times study participants get up early in a particular week, the only
possible values would be whole numbers. It is reasonable to assume that each
participant could get up early 0 to 7 times in any given week but not 1.6 or 5.92
times.
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, PSYC 354
A continuous observation can take on a full range of values (e.g., numbers out to
several decimal places); an infinite number of potential values exists. For example, a
person might complete a task in 12.83912 seconds.The possible values are
continuous, limited only by the number of decimal places we choose to use.
4. What are the 4 levels of measurement? Often, two of these levels are combined into one
level. What is it called, and which 2 original levels are represented by it?
Answer: Nominal, Ordinal, Interval, and Ratio.
Interval and ratio level variables are often referred to togheter as scale
5. List the 4 levels of measurement and describe whether they are discrete or continuous.
Some can be both discrete and continuous.
Nominal: discrete, represents names or categories
Ordinal: discrete, values can be categorized and placed in a meaningful order, but the real
distance between each value is exactly the same.
Interval: continuous, can be put into meaningful order , distance is exactly the same
Ratio: continuous, values where distance between each value is exactly the same and
thereis an absolute zero
6. Identify the level of measurement of given familiar variables (i.e. GPA, city of residence,
etc.) and whether they are discrete or continuous.
7. Remember that the variable is what the researcher is interested in in a study. Be able to
read a study description and identify the variable. For example, a high school math
teacher is interested in how many students go on to study math in college. She decides to
survey alumni contacted through the school records and count how many went on to
study math in college. What is the variable in this study? Is it discrete or continuous?
What level of measurement is this variable? If the teacher conducted this study, what
could a possible value be for the variable? (There’s no one right answer for the last
question; just give an example.)
Independent and Dependent Variables:
1. What is an independent variable?
An IV has a t least two levels that we either manipulate or observe to determine its effects
on the dependent variable.
2. What is a dependent variable?
The DV is the outcome variable that we hypothesize to be related to or caused by changes
in the independent variable.
3. What is the relationship between an independent variable (IV) and a dependent variable
(DV)? We conduct research to see if the independent variable predicts the depedent
variable
4. When discussing independent variables, what does the word “level” refer to?
A level is a discrete value or condition that a variable can take on.
5. A very basic example of an IV and its levels:
a. If a researcher wants to compare the weights of 4 animals on a farm, the
dependent variable (DV) is “Weight.” The independent variable (IV) is
“Animals.” The 4 levels of the IV are Sheep, Cows, Chickens, and Horses. A
possible value of the DV Weight is “120 lbs.”
Page 2 of 6
BIOL 102 EXAM 1 STUDY GUIDE
All exam questions are taken from Modules/Weeks 1 and 2, Nolan and Heinzen. There is no
SPSS content. The study guide is organized by topic.
Populations and Samples:
1. Define what a sample is and identify the sample in a research scenario. For example, in a
study with 15 student participants who have a mean SAT score of 678, what is the
sample? Sample is a set of observations drawn from population of interest. The sample is
15 students
2. What is the letter used to identify the sample size? In other words, the number of
participants in a study is represented by what letter? Letter “n”
3. Explain the difference between a sample and a population. Why are samples used more
often than populations in research? Samples are used most often because reserachers are
rarely able to study evry person in a a population.
Descriptive and Inferential Statistics:
1. Define a descriptive statistic and give an example. Be able to identify a descriptive
statistic in a research scenario. For example, in a study with 15 student participants who
have a mean SAT score of 678, what is the descriptive statistic?
Answer: organizes, summarizes, and communicates agroup of numerical observations.
Mean SAT score of 678
2. Define inferential statistics and explain how they are used by researchers.
Answer: inferential statitics use sample data to make general estimates about the larger
population
3. Understand that the main difference between these two types of statistics (descriptive vs.
inferential) is that one describes and summarizes the data set while the other uses the data
to draw conclusions about a larger population.
Variables and Levels of Measurement:
1. Define a variable.
A variable is any observation of a physical, attitudinal, or behavioral characteristic that
can take on different values.
2. Define a value or score. What is the relationship between a variable and a value? In this
list, which is the variable and which is the value? a. IQ score b. 120
3. What is the difference between a discrete variable and a continuous variable? Can you
give an example of each one and identify why one is discrete while the other is
continuous?
A discrete observation can take on only specific values (e.g., whole numbers); no
other values can exist between these numbers. For example, if we measured the
number of times study participants get up early in a particular week, the only
possible values would be whole numbers. It is reasonable to assume that each
participant could get up early 0 to 7 times in any given week but not 1.6 or 5.92
times.
Page 1 of 6
, PSYC 354
A continuous observation can take on a full range of values (e.g., numbers out to
several decimal places); an infinite number of potential values exists. For example, a
person might complete a task in 12.83912 seconds.The possible values are
continuous, limited only by the number of decimal places we choose to use.
4. What are the 4 levels of measurement? Often, two of these levels are combined into one
level. What is it called, and which 2 original levels are represented by it?
Answer: Nominal, Ordinal, Interval, and Ratio.
Interval and ratio level variables are often referred to togheter as scale
5. List the 4 levels of measurement and describe whether they are discrete or continuous.
Some can be both discrete and continuous.
Nominal: discrete, represents names or categories
Ordinal: discrete, values can be categorized and placed in a meaningful order, but the real
distance between each value is exactly the same.
Interval: continuous, can be put into meaningful order , distance is exactly the same
Ratio: continuous, values where distance between each value is exactly the same and
thereis an absolute zero
6. Identify the level of measurement of given familiar variables (i.e. GPA, city of residence,
etc.) and whether they are discrete or continuous.
7. Remember that the variable is what the researcher is interested in in a study. Be able to
read a study description and identify the variable. For example, a high school math
teacher is interested in how many students go on to study math in college. She decides to
survey alumni contacted through the school records and count how many went on to
study math in college. What is the variable in this study? Is it discrete or continuous?
What level of measurement is this variable? If the teacher conducted this study, what
could a possible value be for the variable? (There’s no one right answer for the last
question; just give an example.)
Independent and Dependent Variables:
1. What is an independent variable?
An IV has a t least two levels that we either manipulate or observe to determine its effects
on the dependent variable.
2. What is a dependent variable?
The DV is the outcome variable that we hypothesize to be related to or caused by changes
in the independent variable.
3. What is the relationship between an independent variable (IV) and a dependent variable
(DV)? We conduct research to see if the independent variable predicts the depedent
variable
4. When discussing independent variables, what does the word “level” refer to?
A level is a discrete value or condition that a variable can take on.
5. A very basic example of an IV and its levels:
a. If a researcher wants to compare the weights of 4 animals on a farm, the
dependent variable (DV) is “Weight.” The independent variable (IV) is
“Animals.” The 4 levels of the IV are Sheep, Cows, Chickens, and Horses. A
possible value of the DV Weight is “120 lbs.”
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