Understanding Independent Variables in Research

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Questions and Answers

What is the main purpose of using observational techniques in a clinical perspective?

To understand and correct particular behavioral problems (correct)

To maintain the anonymity of participants at all times

To conduct randomized experiments on participants

To enforce strict control over the study environment

What is an example of the issues posed by observational techniques?

Inability to read participant thoughts

Lack of participant engagement

High internal validity but low external validity

Reactiveness affecting behavior due to observation (correct)

What distinguishes a clinician from a participant observer in a study?

Clinicians have a personal relationship with participants

Clinicians remain completely unobtrusive during the observation

Participants choose clinicians, while observers choose whom to study (correct)

Both have the same observational responsibilities

Surveys are primarily used to determine what about a population?

The percentage of the population with certain characteristics, beliefs, or behaviors Signup and view all the answers

Which of the following is a limitation of observational techniques?

High external validity but low internal validity Signup and view all the answers

What is one common topic that surveys seek to gather information about?

Personal opinions about political candidates Signup and view all the answers

What is a key characteristic of a descriptive survey?

It aims to measure specific demographic variables Signup and view all the answers

What outcome was noted from after-death phone calls to families of people with mental illness?

Heightened feelings of validation and comfort Signup and view all the answers

How does the order in which items are presented affect responses in a study?

It affects responses due to the position in the series. Signup and view all the answers

Which statement correctly describes carryover effects?

They involve the influence of previous events on subsequent responses. Signup and view all the answers

What is an example of an environmental independent variable?

Examining whether changing lighting conditions affects worker performance Signup and view all the answers

What is a key characteristic of complete counterbalancing?

Each event must be presented an equal number of times to each participant. Signup and view all the answers

Which of the following correctly describes a dependent variable?

It must be operationally definable and relate back to your hypothesis. Signup and view all the answers

According to the empirical rule, what percentage of data lies within two standard deviations from the mean in a bell-shaped distribution?

95% Signup and view all the answers

How does age serve as a participant/subject independent variable?

It can influence the abilities of individuals to make safe decisions. Signup and view all the answers

Which type of dependent variable measures how often an event occurs?

Rate/frequency Signup and view all the answers

In the example of the empirical rule given, what was the sample mean height of women in Canada?

64 inches Signup and view all the answers

What must be true about events in complete counterbalancing aside from equal occurrence?

Each event must precede and follow all other events an equal number of times. Signup and view all the answers

What does the term 'latency' refer to in the context of dependent variables?

The amount of time until a response occurs Signup and view all the answers

When assessing the risk behavior of various age groups in traffic situations, which age category is least likely to cross the road safely?

Older adults (>75 years) Signup and view all the answers

What is one common method used in descriptive research?

Utilizing census data for statistical inference. Signup and view all the answers

What is a main focus of observational research methods?

Recording natural behavior without interference. Signup and view all the answers

In the study examining road crossing behavior, what was measured as a dependent variable?

The willingness of participants to cross the road Signup and view all the answers

What type of study design often involves manipulation of training types, such as for teaching abduction-prevention skills?

Experience IVs Signup and view all the answers

Which of the following percentages indicates data lying within one standard deviation from the mean according to the empirical rule?

68% Signup and view all the answers

What is the primary goal of counterbalancing in research?

To control for order effects. Signup and view all the answers

What was the total number of judgments made in the case presented?

25 Signup and view all the answers

What does the graph depicting homicides in Canada by province represent?

Homicides per 100,000 residents by province Signup and view all the answers

Which of the following is a critical issue when interpreting visual data representation?

Failing to adjust for distorting confounds Signup and view all the answers

In the presented graph, which province likely has the highest homicide rate relative to others?

British Columbia Signup and view all the answers

How should results be visually represented to avoid misrepresentation?

Providing accurate scales and context Signup and view all the answers

What is a potential consequence of misinterpreting graphical data?

Misinformed public perception Signup and view all the answers

If a province had 10 homicides per 100,000 people and another had 20, what can be assumed?

The second province has approximately double the homicide rate Signup and view all the answers

What factor must be considered to ensure accuracy in visual data?

Adjusting for confounds Signup and view all the answers

What does each point in a scatter plot represent in this context?

The relationship between petal length and petal width of one flower Signup and view all the answers

What does negative skew imply about a distribution?

The long tail of the distribution extends to the left Signup and view all the answers

Which of the following describes kurtosis?

The extent of deviation from the normal curve in width and tail thickness Signup and view all the answers

What is the main goal of using graphs in data representation?

To offer an accurate visual representation of results Signup and view all the answers

What is a common feature of 'cheating graphs'?

They distort visual representation to mislead viewers. Signup and view all the answers

What characteristic typically defines a unimodal symmetrical distribution?

The data is spread equally around the mean. Signup and view all the answers

How can data distortion occur in graph usage?

By using inappropriate scales or factors Signup and view all the answers

Which type of distribution is described as 'tall and skinny'?

Normal distribution with high kurtosis Signup and view all the answers

Study Notes

Experience IVs

Manipulation of the amount or type of training or learning
Example: Testing a school program for teaching children abduction-prevention skills

Stimulus/Environmental IVs

Manipulation of some aspect of the environment
Example: Examining the effects of changing various conditions on worker performance
Example: Looking at whether the presence of a weapon decreases ID accuracy

Participant/Subject IVs

Aspects of the participant treated as if they are IVs
Some examples: Age, gender, personality traits

Participant/Subject IV Example

Overrepresentation by older pedestrians in serious injury and fatal crashes may be due to age-related diminished ability to select gaps in oncoming traffic for safe road crossing
Participants tested in three groups: young (30-45 yrs), young-old (60-69 yrs), and old-old (>75 yrs).
Despite an apparent ability to process the distance and speed of oncoming traffic when given enough time, significantly more old-old adults were willing to cross the road when there was an insufficiently safe gap.

Dependent Variables

Variable that is measured to see the effects of the independent variable
Should relate back to your hypothesis
Must be operationally definable
Must be both VALID and RELIABLE

Types of DVs

Correctness: How many were right?
Rate/Frequency: How often did it occur within a certain amount of time?
Degree or Amount: How much of it was there?
Latency or Duration: How fast did it happen? How long did it last?

Order Effects

When position in a series affects how participants respond
Doesn't depend on the EVENT but rather the POSITION

Carryover Effects

When the effects of one event influence responses to the next event
Depends on the EVENT not the POSITION

Counterbalancing

Vary the order in which items are presented
Can be either within-subject or within-group
Can be either complete or incomplete

Complete Counterbalancing

Each event must be presented to each participant an equal number of times
Each event must occur an equal number of times at each session
Each event must precede and follow all other events an equal number of times

Interpreting Standard Deviation: Empirical Rule (68 – 95 – 99.7 Rule)

About 68% of the data lie within 1 SD of the mean
About 95% of the data lie within 2 SDs of the mean
About 99.7% of the data lie within 3 SDs of the mean

Example: Using the Empirical Rule

In a survey conducted by the Stats Canada, the sample mean height of women in Canada (ages 20-29) was 64 inches, with a sample standard deviation of 2.71 inches
Estimate the percent of the women whose heights are between 64 inches and 69.42 inches

Solution: Using the Empirical Rule

Because the distribution is bell-shaped, you can use the Empirical Rule

Non-Experimental Methods I: Observational Research

Using Census data to determine whether lower income families are more likely to have health problems
Recording the behaviour of children on the playground to determine the prevalence of bullying
Detailed observations of the abilities and behaviour of a man with synesthesia
Jane Goodall's research of chimpanzees in the wild

Observational Techniques: Clinical Perspective

Descriptive approach aimed at understanding and correcting a particular behavioural problem
Example: Does an “after-death” phone call help family members of a person with mental illness?
Noted increased feelings of validation, comfort, and thankfulness to mental health provider for the call.
Based on these findings, the authors recommended that after-death calls should be made in the future.

Observational Techniques: Issues

Reactivity: When knowledge one is being observed affects his/her behaviour (AKA “The Hawthorne Effect”)
Objectivity
Cannot make cause-and-effect statements

Surveys & Questionnaires: Descriptive Surveys

Seek to determine what % of the population have particular characteristics, beliefs, or behaviours
Examples:
- Who are you? Do you live alone? How many children do you have?
- Do you suffer from depression? Diabetes? Asthma?
- Do you have a driver’s license? Are you employed?
- What do you think? Do you believe in gay marriage? Which do you like better? Pepsi or Coke?
- Who do you think will win the Stanley Cup? How would you rate the service at this restaurant?
- Who do you plan to vote for?

Describing Distributions

Unimodal Symmetrical
Bimodal Symmetrical
Negative Skew
Positive Skew
Kurtosis: Extent of deviation from normal curve in width of curve and thickness of tails
- Normal Distribution
- Tall and skinny versus flat and wide

Effective and Accurate Use of Graphs

Goal of graphs: To provide an ACCURATE visual representation of your results
Not all graphs are created equal! Some common ways that people use graphs to distort data...

Cheating Graphs

Problem 1: Distortion of the Y axis scale
Problem 2: Failure to use the same scale for all comparisons
Problem 3: Failing to adjust for distorting confounds (e.g., population sizes)

Reminders and Announcements

Midterm: October 25th
- 25 multiple choice questions, 5 short answer questions
- Do the practice questions posted on D2L.
- More practice questions will be uploaded this week and the next as we approach the midterm date.
Review sessions on October 23rd and October 24th
Go over list of important topics to study.

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Description

This quiz explores the concept of independent variables in research, focusing on experience, stimulus/environmental factors, and participant traits. Learn how these variables impact study outcomes through real-world examples and case studies. Test your knowledge on how manipulating these factors can lead to insightful findings.