Week 4 - PSYCHOLOGICAL MEASUREMENT Flashcards
Describe - The Rosenberg Self-Esteem Scale
(Rosenberg, 1989)[2] is one of the most common measures of self-esteem
Participants respond to each of the 10 items that follow with a rating on a 4-point scale: Strongly Agree, Agree, Disagree, Strongly Disagree
Describe ‘measurement’ in psychometrics and give an example…
so that the scores represent some characteristic of the individuals.
PSYCHOMETRICS EXAMPLE
Imagine — Cognitive psychologist - measure - person’s working memory capacity—their ability to hold in mind and think about several pieces of information all at the same time. (% & @ # ^)
To do this, she might use a backward digit span task, in which she reads a list of two digits to the person and asks them to repeat them in reverse order. She then repeats this several times, increasing the length of the list by one digit each time, until the person makes an error.
The length of the longest list for which the person responds correctly is the score and
REPRESENTS their working memory capacity.
(EXAMPLE: Beck Depression Inventory, which is a 21-item self-report questionnaire in which the person rates the extent to which they have felt sad, lost energy, and experienced other symptoms of depression over the past 2 weeks.
SUM = represents the person’s current level of depression.)
Requires - SYSTEMATIC procedure for assigning scores to individuals or objects…
(1 = # // 2 = * // 3 = $)
SO… those scores represent the = ** characteristic of interest**.
Describe psychological constructs and give examples
Psychological Constructs
Variables that aren’t easy to quantify
These kinds of variables are called constructs (pronounced CON-structs)
EXAMPLE
#Personality traits (e.g., extraversion)
:) emotional states (e.g., fear)
» attitudes (e.g., toward taxes)
(*) abilities (e.g., athleticism).
Describe and give example - Psychological Constructs
Psychological constructs :
- cannot be observed directly
- often represent tendencies to think, feel, or act in certain ways
- often involve internal processes
EXAMPLE
FEAR - activates central and peripheral nervous system structures, AND certain kinds of thoughts, feelings, and behaviors…
NOT OBVIOUS TO AN OBSERVER
IMPORTANT NOTE -
Neither extraversion nor fear “reduces to” any particular thought, feeling, act, or physiological structure or process.
INSTEAD each is a kind of summary of a
COMPLEX SET set of behaviors and internal processes.
Describe and give example - Conceptual definition
The conceptual definition of a psychological construct describes…
the behaviors and internal processes that MAKE UP that construct, along with HOW IT RELATES to other variables.
EXAMPLE:
A conceptual definition of NEUROTICISM (another one of the Big Five) = people’s tendency to experience negative emotions such as anxiety, anger, and sadness across a variety of situations.
This definition might ALSO INCLUDE that it has a strong genetic component, remains fairly stable over time, and is positively correlated with the tendency to experience pain and other physical symptoms.
(EG. The Big Five is a set of five broad dimensions that capture much of the variation in human personality. Each of the Big Five can even be defined in terms of six more specific constructs called “facets” (Costa & McCrae, 1992))
Why use a conceptual definition instead of using the dictionary?
Many scientific constructs do not have counterparts in everyday language (e.g., working memory capacity).
Researchers are in the business of developing definitions that are;
—more detailed and precise
—and that more accurately describe the way the world is—than the informal definitions in the dictionary.
As we will see, they do this by
1. PROPOSING conceptual definitions
2. Testing them empirically
3. Revising them as necessary
Sometimes they throw them out altogether.
This is why the RESEARCH LITERATURE often includes different conceptual definitions of the same construct.
In some cases, an older conceptual definition has been replaced by a newer one that fits and works better.
In others, researchers are still in the process of deciding which of various conceptual definitions is the best.
Describe operational definition (and 3 measure categories)
An operational definition is a
definition of a variable in terms of precisely how it is to be measured.
These measures generally fall into one of three broad categories.
Self-report measures are those in which PARTICIPANTS REPORT on their own thoughts, feelings, and actions, as with the Rosenberg Self-Esteem Scale (Rosenberg, 1965)[2].
Behavioral measures are those in which some OTHER aspect of participants’ behavior is
OBSERVED & RECORDED.
EXAMPLE
Lab - measuring working memory capacity using the backward digit span task.
Natural Setting - Physical aggression from researcher Albert Bandura and his colleagues (Bandura, Ross, & Ross, 1961)[3].
They let each of several children play for 20 minutes in a room that contained a clown-shaped punching bag called a Bobo doll. They filmed each child and counted the number of acts of physical aggression the child committed. These included hitting the doll with a mallet, punching it, and kicking it. Their operational definition, then, was the number of these specifically defined acts that the child committed during the 20-minute period.
Physiological measures are those that involve recording any of a wide variety of physiological processes, EG.
<3 Heart rate
~~~ BLOOD pressure
/// electrical activity ///
For ANY VARIABLE OR CONSTRUCT, there will be multiple operational definitions - Give an example
For ANY VARIABLE OR CONSTRUCT, there will be multiple operational definitions.
EXAMPLE - STRESS
conceptual definition = stress is an adaptive response to a *perceived danger or threat *that involves physiological, cognitive, affective, and behavioral components.
Opreational Definition
**The Social Readjustment Rating Scale **(Holmes & Rahe, 1967)[4] is a self-report questionnaire on which people identify stressful events that they have experienced in the past year and assigns points for each one depending on its severity.
For example, a man who has been divorced (73 points), changed jobs (36 points), and had a change in sleeping habits (16 points) in the past year would have a total score of 125.
The Hassles and Uplifts Scale (Delongis, Coyne, Dakof, Folkman & Lazarus, 1982) [5] is similar but focuses on everyday stressors like misplacing things and being concerned about one’s weight.
The Perceived Stress Scale (Cohen, Kamarck, & Mermelstein, 1983) [6] is another self-report measure that focuses on people’s feelings of stress (e.g., “How often have you felt nervous and stressed?”).
Researchers have also operationally defined stress in terms of several physiological variables including blood pressure and levels of the stress hormone cortisol.
Describe converging operations
When psychologists use multiple operational definitions of the same construct—either within a study or across studies—they are using converging operations.
The idea is that the VARIOUS operational definitions are “converging” or coming together on the same construct.
- When scores based on several different operational definitions are closely related to each other
- and produce similar patterns of results,
- this constitutes good evidence that the construct is being measured effectively
- and that it is useful.
EXAMPLE - various measures of stress, are all correlated with each other and have all been shown to be correlated with other variables such as** immune system functioning** (also measured in a variety of ways) (Segerstrom & Miller, 2004)[7].
Name the four levels of measurement and describe their genesis
Levels of Measurement
The psychologist S. S. Stevens suggested that scores can be assigned to individuals in a way that communicates more or less quantitative information about the variable of interest (Stevens, 1946)[8]. (He proposes four levels)
The nominal level
The ordinal level
The interval level
The ratio level
Describe and give examples - The nominal level
The nominal level of measurement is used for categorical variables and involves
ASSIGNING SCORES = that are **category labels. **
CATEGORY LABELS communicate whether any two individuals are the same or different in terms of the variable being measured.
EXAMPLE
Asking about **marital status or ethnicity **
NO implied order (one is not higher than the other
Responses are merely categorized.
Nominal scales thus embody the LOWEST level of measurement
Describe and give examples - The ordinal level
ORDINAL = ORDER (Rank order)
Ordinal level of measurement involves ASSIGN SCORES so that they represent the rank order of the individuals.
Ranks communicates whether one individual variable is higher or lower on that variable.
EXAMPLE -
APP REVIEW Questions - “very dissatisfied,” “somewhat dissatisfied,” “somewhat satisfied,” or “very satisfied.” The items in this scale are ordered, ranging from least to most satisfied.
Describe ordinal level limitations
EXAMPLE
The DIFFERENCE between two levels of an ordinal scale cannot be assumed to be the same as the difference between two other levels
In our satisfaction scale…
The difference between the responses “very dissatisfied” and “somewhat dissatisfied” is probably not equivalent to the difference between “somewhat dissatisfied” and “somewhat satisfied.”
Nothing in our measurement procedure allows us to determine whether the two differences reflect the same difference in psychological satisfaction.
Statisticians express this point by saying that the differences between adjacent scale values do not necessarily represent equal intervals on the underlying scale giving rise to the measurements.
(In our case, the underlying scale is the true feeling of satisfaction, which we are trying to measure.)
Describe interval level of measurement
The interval level of measurement involves assigning scores using **numerical scales **in which intervals have the same interpretation throughout.
EXAMPLE
Fahrenheit or Celsius temperature scales.
The difference between 30 degrees and 40 degrees represents the same temperature difference as the difference between 80 degrees and 90 degrees.
This is because each 10-degree interval has the same physical meaning (in terms of the kinetic energy of molecules).
Describe the limitations of interval scales
Interval scales are not perfect, however.
In particular, they do not have a true zero point even if one of the scaled values happens to carry the name “zero.”
EXAMPLE
Measuring IQ - Someone may get a ‘0’ score but it doesn’t indicate the complete absense of intellect.
The Fahrenheit scale illustrates the issue. Zero degrees Fahrenheit does not represent the complete absence of temperature (the absence of any molecular kinetic energy).
In reality, the label “zero” is applied to its temperature for quite accidental reasons connected to the history of temperature measurement.
Since an interval scale has no true zero point, it does not make sense to compute ratios of temperatures.
