- Define measurement and give several examples of measurement in psychology.
- Explain what a psychological construct is and give several examples.
- Distinguish conceptual from operational definitions, give examples of each, and create simple operational definitions.
- Distinguish the four levels of measurement, give examples of each, and explain why this distinction is important.
What Is Measurement?
Measurementis the assignment of scores to individuals so that the scores represent some characteristic of the individuals. This very general definition is consistent with the kinds of measurement that everyone is familiar with—for example, weighing oneself by stepping onto a bathroom scale, or checking the internal temperature of a roasting turkey by inserting a meat thermometer. It is also consistent with measurement in the other sciences. In physics, for example, one might measure the potential energy of an object in Earth’s gravitational field by finding its mass and height (which of course requires measuringthosevariables) and then multiplying them together along with the gravitational acceleration of Earth (9.8 m/s2). The result of this procedure is a score that represents the object’s potential energy.
This general definition of measurement is consistent with measurement in psychology too. (Psychological measurement is often referred to as psychometrics.) Imagine, for example, that a cognitive psychologist wants to measure a person’s working memory capacity—his or her 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 him or her 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 his or her working memory capacity. Or imagine a clinical psychologist who is interested in how depressed a person is. He administers the Beck Depression Inventory, which is a 21-item self-report questionnaire in which the person rates the extent to which he or she has felt sad, lost energy, and experienced other symptoms of depression over the past 2 weeks. The sum of these 21 ratings is the score and represents his or her current level of depression.
The important point here is that measurement does not require any particular instruments or procedures. It does not require placing individuals or objects on bathroom scales, holding rulers up to them, or inserting thermometers into them. What itdoesrequire issomesystematic procedure for assigning scores to individuals or objects so that those scores represent the characteristic of interest.
Many variables studied by psychologists are straightforward and simple to measure. These include sex, age, height, weight, and birth order. You can often tell whether someone is male or female just by looking. You can ask people how old they are and be reasonably sure that they know and will tell you. Although people might not know or want to tell you how much they weigh, you can have them step onto a bathroom scale. Other variables studied by psychologists—perhaps the majority—are not so straightforward or simple to measure. We cannot accurately assess people’s level of intelligence by looking at them, and we certainly cannot put their self-esteem on a bathroom scale. These kinds of variables are calledconstructs(pronouncedCON-structs) and include personality traits (e.g., extraversion), emotional states (e.g., fear), attitudes (e.g., toward taxes), and abilities (e.g., athleticism).
Psychological constructs cannot be observed directly. One reason is that they often representtendenciesto think, feel, or act in certain ways. For example, to say that a particular university student is highly extraverted does not necessarily mean that she is behaving in an extraverted way right now. In fact, she might be sitting quietly by herself, reading a book. Instead, it means that she has a general tendency to behave in extraverted ways (talking, laughing, etc.) across a variety of situations. Another reason psychological constructs cannot be observed directly is that they often involve internal processes. Fear, for example, involves the activation of certain central and peripheral nervous system structures, along with certain kinds of thoughts, feelings, and behaviors—none of which is necessarily obvious to an outside observer. Notice also that 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 of behaviors and internal processes.
The Big Five
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).
Figure 4.1 The Big Five Personality Dimensions
Theconceptualdefinitionof a psychological construct describes the behaviors and internal processes that make up that construct, along with how it relates to other variables. For example, a conceptual definition of neuroticism (another one of the Big Five) would be that it is 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.
Students sometimes wonder why, when researchers want to understand a construct like self-esteem or neuroticism, they do not simply look it up in the dictionary. One reason is that many scientific constructs do not have counterparts in everyday language (e.g., working memory capacity). More important, 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 proposing conceptual definitions, testing them empirically, and 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.
Anoperationaldefinitionis 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-reportmeasuresare those in which participants report on their own thoughts, feelings, and actions, as with the Rosenberg Self-Esteem Scale. Behavioral measuresare those in which some other aspect of participants’ behavior is observed and recorded. This is an extremely broad category that includes the observation of people’s behavior both in highly structured laboratory tasks and in more natural settings. A good example of the former would be measuring working memory capacity using the backward digit span task. A good example of the latter is a famous operational definition of physical aggression from researcher Albert Bandura and his colleagues (Bandura, Ross, & Ross, 1961). 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 he or she 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. Finally,physiologicalmeasuresare those that involve recording any of a wide variety of physiological processes, including heart rate and blood pressure, galvanic skin response, hormone levels, and electrical activity and blood flow in the brain.
For any given variable or construct, there will be multiple operational definitions. Stress is a good example. A rough conceptual definition is that stress is an adaptive response to a perceived danger or threat that involves physiological, cognitive, affective, and behavioral components. But researchers have operationally defined it in several ways. The Social Readjustment Rating Scale 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 Daily Hassles and Uplifts Scale is similar but focuses on everyday stressors like misplacing things and being concerned about one’s weight. The Perceived Stress Scale 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.
When psychologists use multiple operational definitions of the same construct—either within a study or across studies—they are using convergingoperations. 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. The various measures of stress, for example, 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). This is what allows researchers eventually to draw useful general conclusions, such as “stress is negatively correlated with immune system functioning,” as opposed to more specific and less useful ones, such as “people’s scores on the Perceived Stress Scale are negatively correlated with their white blood counts.”
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). For example, the officials at a 100-m race could simply rank order the runners as they crossed the finish line (first, second, etc.), or they could time each runner to the nearest tenth of a second using a stopwatch (11.5 s, 12.1 s, etc.). In either case, they would be measuring the runners’ times by systematically assigning scores to represent those times. But while the rank ordering procedure communicates the fact that the second-place runner took longer to finish than the first-place finisher, the stopwatch procedure also communicateshow muchlonger the second-place finisher took. Stevens actually suggested four different levelsofmeasurement(which he called “scales of measurement”) that correspond to four different levels of quantitative information that can be communicated by a set of scores.
Thenominallevelof 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. For example, if you look at your research participants as they enter the room, decide whether each one is male or female, and type this information into a spreadsheet, you are engaged in nominal-level measurement. Or if you ask your participants to indicate which of several ethnicities they identify themselves with, you are again engaged in nominal-level measurement. The essential point about nominal scales is that they do not imply any ordering among the responses. For example, when classifying people according to their favorite color, there is no sense in which green is placed “ahead of” blue. Responses are merely categorized. Nominal scales thus embody the lowest level of measurement.
The remaining three levels of measurement are used for quantitative variables. Theordinallevelof measurement involves assigning scores so that they represent the rank order of the individuals. Ranks communicate not only whether any two individuals are the same or different in terms of the variable being measured but also whether one individual is higher or lower on that variable. For example, a researcher wishing to measure consumers’ satisfaction with their microwave ovens might ask them to specify their feelings as either “very dissatisfied,” “somewhat dissatisfied,” “somewhat satisfied,” or “very satisfied.” The items in this scale are ordered, ranging from least to most satisfied. This is what distinguishes ordinal from nominal scales. Unlike nominal scales, ordinal scales allow comparisons of the degree to which two individuals rate the variable. For example, our satisfaction ordering makes it meaningful to assert that one person is more satisfied than another with their microwave ovens. Such an assertion reflects the first person’s use of a verbal label that comes later in the list than the label chosen by the second person.
On the other hand, ordinal scales fail to capture important information that will be present in the other levels of measurement we examine. In particular, the difference between two levels of an ordinal scale cannot be assumed to be the same as the difference between two other levels (just like you cannot assume that the gap between the runners in first and second place is equal to the gap between the runners in second and third place). In our satisfaction scale, for example, 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.)
Theintervallevelof measurement involves assigning scores using numerical scales in which intervals have the same interpretation throughout. As an example, consider either the 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).
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.” 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. For example, there is no sense in which the ratio of 40 to 20 degrees Fahrenheit is the same as the ratio of 100 to 50 degrees; no interesting physical property is preserved across the two ratios. After all, if the “zero” label were applied at the temperature that Fahrenheit happens to label as 10 degrees, the two ratios would instead be 30 to 10 and 90 to 40, no longer the same! For this reason, it does not make sense to say that 80 degrees is “twice as hot” as 40 degrees. Such a claim would depend on an arbitrary decision about where to “start” the temperature scale, namely, what temperature to call zero (whereas the claim is intended to make a more fundamental assertion about the underlying physical reality). In psychology, the intelligence quotient (IQ) is often considered to be measured at the interval level.
Finally, theratiolevelof measurement involves assigning scores in such a way that there is a true zero point that represents the complete absence of the quantity. Height measured in meters and weight measured in kilograms are good examples. So are counts of discrete objects or events such as the number of siblings one has or the number of questions a student answers correctly on an exam. You can think of a ratio scale as the three earlier scales rolled up in one. Like a nominal scale, it provides a name or category for each object (the numbers serve as labels). Like an ordinal scale, the objects are ordered (in terms of the ordering of the numbers). Like an interval scale, the same difference at two places on the scale has the same meaning. However, in addition, the same ratio at two places on the scale also carries the same meaning (see Table 4.1).
The Fahrenheit scale for temperature has an arbitrary zero point and is therefore not a ratio scale. However, zero on the Kelvin scale is absolute zero. This makes the Kelvin scale a ratio scale. For example, if one temperature is twice as high as another as measured on the Kelvin scale, then it has twice the kinetic energy of the other temperature.
Another example of a ratio scale is the amount of money you have in your pocket right now (25 cents, 50 cents, etc.). Money is measured on a ratio scale because, in addition to having the properties of an interval scale, it has a true zero point: if you have zero money, this actually implies the absence of money. Since money has a true zero point, it makes sense to say that someone with 50 cents has twice as much money as someone with 25 cents.
Stevens’s levels of measurement are important for at least two reasons. First, they emphasize the generality of the concept of measurement. Although people do not normally think of categorizing or ranking individuals as measurement, in fact, they are as long as they are done so that they represent some characteristic of the individuals. Second, the levels of measurement can serve as a rough guide to the statistical procedures that can be used with the data and the conclusions that can be drawn from them. With nominal-level measurement, for example, the only available measure of central tendency is the mode. Also, ratio-level measurement is the only level that allows meaningful statements about ratios of scores. One cannot say that someone with an IQ of 140 is twice as intelligent as someone with an IQ of 70 because IQ is measured at the interval level, but one can say that someone with six siblings has twice as many as someone with three because number of siblings is measured at the ratio level.
|Level of Measurement||Category labels||Rank order||Equal intervals||True zero|
- Measurement is the assignment of scores to individuals so that the scores represent some characteristic of the individuals. Psychological measurement can be achieved in a wide variety of ways, including self-report, behavioral, and physiological measures.
- Psychological constructs such as intelligence, self-esteem, and depression are variables that are not directly observable because they represent behavioral tendencies or complex patterns of behavior and internal processes. An important goal of scientific research is to conceptually define psychological constructs in ways that accurately describe them.
- For any conceptual definition of a construct, there will be many different operational definitions or ways of measuring it. The use of multiple operational definitions, or converging operations, is a common strategy in psychological research.
- Variables can be measured at four different levels—nominal, ordinal, interval, and ratio—that communicate increasing amounts of quantitative information. The level of measurement affects the kinds of statistics you can use and conclusions you can draw from your data.
- Practice: Complete the Rosenberg Self-Esteem Scale and compute your overall score.
- Practice: Think of three operational definitions for sexual jealousy, decisiveness, and social anxiety. Consider the possibility of self-report, behavioral, and physiological measures. Be as precise as you can.
- Practice: For each of the following variables, decide which level of measurement is being used.
- An university instructor measures the time it takes herstudents to finish an exam by looking through the stack of exams at the end. She assigns the one on the bottom a score of 1, the one on top of that a 2, and so on.
- A researcher accesses her participants’ medical records and counts the number of times they have seen a doctor in the past year.
- Participants in a research study are asked whether they are right-handed or left-handed.
- Costa, P. T., Jr., & McCrae, R. R. (1992). Normal personality assessment in clinical practice: The NEO Personality Inventory. Psychological Assessment, 4, 5–13. ↵
- Bandura, A., Ross, D., & Ross, S. A. (1961). Transmission of aggression through imitation of aggressive models. Journal of Abnormal and Social Psychology, 63, 575–582. ↵
- Segerstrom, S. E., & Miller, G. E. (2004). Psychological stress and the human immune system: A meta-analytic study of 30 years of inquiry. Psychological Bulletin, 130, 601–630. ↵
- Stevens, S. S. (1946). On the theory of scales of measurement. Science, 103, 677–680. ↵
- Levels of Measurement. Retrieved from http://wikieducator.org/Introduction_to_Research_Methods_In_Psychology/Theories_and_Measurement/Levels_of_Measurement ↵
What is psychological measurement in psychology? ›
Psychological measurement focuses on developing and testing tools to validity measure psychological qualities (such as knowledge, attitudes and opinions, emotions, cognitions, and personality).What is measurement in psychological research? ›
Measurement is the assignment of scores to individuals so that the scores represent some characteristic of the individuals. Psychological measurement can be achieved in a wide variety of ways, including self-report, behavioral, and physiological measures.What are the 3 main measurements options psychologists use in research? ›
In psychology and many disciplines that draw on psychology, data is classified as having one of four measurement scale types: nominal, ordinal, interval, and ratio.What is psychological measurement quizlet? ›
Definition. 1 / 10. assignment of scores to individuals so that the scores represent some characteristic of the individuals; requires some systematic procedure for assigning scores to individuals or objects so that. those scores represent the characteristic of interest. Psychometrics: psychological measurement.What is an example of psychological measurement? ›
(Psychological measurement is often referred to as psychometrics .) Imagine, for example, that a cognitive psychologist wants to measure a person's working memory capacity—his or her ability to hold in mind and think about several pieces of information all at the same time.What is the purpose of psychological measurement? ›
Psychological testing may sound intimidating, but it's designed to help you. Psychologists use tests and other assessment tools to measure and observe a patient's behavior to arrive at a diagnosis and guide treatment.What is the main purpose of measurement in research? ›
Summary. The goal of measurement is to get reliable data with which to answer research questions and assess theories of change.What are the principles of psychological measurement? ›
Important principles of psychological measurement and assessment are covered, including: standardisation, norms, reliability, test development and validation.What are the types of measurement in research? ›
You can see there are four different types of measurement scales (nominal, ordinal, interval and ratio).What are the 4 types of scales commonly used as levels of measurement in research? ›
Scales of measurement is how variables are defined and categorised. Psychologist Stanley Stevens developed the four common scales of measurement: nominal, ordinal, interval and ratio. Each scale of measurement has properties that determine how to properly analyse the data.
What are the 4 levels of measurement psychology? ›
Psychologist Stanley Smith is known for developing four levels of measurement: nominal, ordinal, interval, and ratio.What are the 5 types of measurements? ›
- Indirect method of measurement.
- Direct method of measurement.
- Fundamental method of measurement.
- Substitution method of measurement.
- Comparison method of measurement.
Reliability and validity are typically considered the two most important psychometric properties of tests. While they can be applied to any test, historically their importance results from the field's emphasis on selection tests.What is the measurement problem in psychology? ›
In psychology, measurement is especially difficult because what we want to measure often does not permit direct observation. We can directly observe the height of a person next to us on the bus, but we often have little insight into latent, psychological attributes such as intelligence, extraversion, or depression.What scales of measurement are most commonly used in psychological research? ›
As a reminder, most applied studies in psychology use ordinal measurements but apply methods that are only permissible for interval scale data.What is the most common method of measurement in personality psychology research? ›
The first type—which easily is the most widely used in modern personality research—asks people to describe themselves. This approach offers two key advantages. First, self-raters have access to an unparalleled wealth of information: After all, who knows more about you than you yourself?
Physiological measures permit a more objective workload assessment and can provide “real- time” evaluation, thus allowing the system designer to quickly and accurately identify usability problems as they occur .Why are psychological methods important? ›
Applying the scientific method to psychology, therefore, helps to standardize the approach to understanding its very different types of information. The scientific method allows psychological data to be replicated and confirmed in many instances, under different circumstances, and by a variety of researchers.What are the three most important reason for measurement? ›
The most common answers are: 1) to answer questions, 2) to show results, 3) to demonstrate value, 4) to justify our budget (or existence), 5) to identify opportunities for improvement and 6) to manage results.Why are measurements important short answer? ›
Also measuring certain things correctly is very necessary including distance, time, and accuracy. We can really know the universe around us by measuring such occurrences or, in other words, by taking such measurements. Measurements may also enable us to make decisions on the basis of the measurement result.
Why is it important for measurements in research to be accurate or valid? ›
Measurement accuracy (i.e., validity) is essential in order to guarantee the quality and integrity of the research findings. Definition: Accuracy (i.e., validity) refers to whether or not an instrument or method truly measures what you think it measures.What is the role of psychological measurement in society? ›
The goals of psychological assessment are to better understand a person's strengths and weaknesses, identify potential problems with cognitions, emotional reactivity, and make recommendations for treatment/remediation.What is the process of measurement in research? ›
Broadly speaking, there are four steps in the measurement process: (a) conceptually defining the construct, (b) operationally defining the construct, (c) implementing the measure, and (d) evaluating the measure.What is the meaning of measurement in research give examples? ›
Measurement is the process of observing and recording the observations that are collected as part of a research effort. There are two major issues that will be considered here. First, you have to understand the fundamental ideas involved in measuring. Here we consider two of major measurement concepts.What are the 4 types of scales with examples? ›
Each of the four scales (i.e., nominal, ordinal, interval, and ratio) provides a different type of information. Measurement refers to the assignment of numbers in a meaningful way, and understanding measurement scales is important to interpreting the numbers assigned to people, objects, and events.What are four levels of measurement in qualitative research? ›
There are four levels of measurement – nominal, ordinal, and interval/ratio – with nominal being the least precise and informative and interval/ratio variable being most precise and informative.How do you measure variables in research? ›
Statistical variables can be measured using measurement instruments, algorithms, or even human discretion. How we measure variables are called scale of measurements, and it affects the type of analytical techniques that can be used on the data, and conclusions that can be drawn from it.What are the four levels of measurement choose 4 answers? ›
- Nominal: the data can only be categorized.
- Ordinal: the data can be categorized and ranked.
- Interval: the data can be categorized and ranked, and evenly spaced.
- Ratio: the data can be categorized, ranked, evenly spaced and has a natural zero.
Levels of Measurement: Nominal, Ordinal, Interval and Ratio | Indeed.com.What are the four measurements that we measure most? ›
The Big Ideas
The basic units of measurement are for length, mass, time and temperature.
What are the 3 parts of measurement? ›
So a measured number has 3 parts; magnitude, unit and entity.What is a measurement short answer? ›
Measurement is a comparison of an unknown quantity with a known fixed quantity of the same kind. The value obtained on measuring a quantity is called its magnitude. The magnitude of a quantity is expressed in numbers and in its unit.What are the basic method of measurement? ›
There are two methods for performing dimensional measurements: direct measurement and indirect measurement. With direct measurements, measuring instruments such as Vernier calipers, micrometers, and coordinate measuring machines are used to measure the dimensions of the target directly.What level of measurement is used for psychological variables? ›
In 1946, Stevens observed that psychological measurement, such as measurement of opinions, usually operates on ordinal scales; thus means and standard deviations have no validity, but they can be used to get ideas for how to improve operationalization of variables used in questionnaires.
Minnesota Multiphasic Personality Inventory (MMPI-2)
First published in 1989, the MMPI-2 is the world's most widely used psychometric test for measuring mental health ailments that feature as forms of psychopathology (Rogers, Robinson, & Jackson, 2016).
Which of the following BEST defines measurement in psychology? Assessing thoughts, feelings or behaviors.What causes measurement error in research? ›
A variety of sources can cause measurement error, including response styles, specifically acquiescence, disacquiescence, extreme response, response range, midpoint responding, and noncontingent responding (Baumgartner & Steenkamp, 2001; Podsakoff, MacKenzie, Lee, & Podsakoff, 2003).What are examples of measurement errors in research? ›
In most cases, measurement errors are comprised of systematic and random errors. To get a better idea of what a measurement error is let's look at an example: if an electronic scale is loaded with 1kg of standard weight and the reading is 10002 grams, then the measurement error is = (1002 grams – 1000 grams) = 2 grams.What are psychophysiological measurements? ›
Psychophysiological Measures. Psychophysiological measures are physiological responses of human body to psychological manipulations . Actually, these responses are physical signals that make possible to determine humans' psychological processes by monitoring their bodily changes.What are the 3 types of measurement? ›
You can see there are four different types of measurement scales (nominal, ordinal, interval and ratio).
What are the levels of psychological measurement? ›
Psychologist Stanley Smith is known for developing four levels of measurement: nominal, ordinal, interval, and ratio.What factors affect physiological measurements? ›
Factors affecting changes in physiological measurements, e.g. illnesses and infections, stress, anxiety, lifestyle factors, medication, age, environment, time of day.What are the four types of scales of measurement used in psychological research? ›
Scales of measurement is how variables are defined and categorised. Psychologist Stanley Stevens developed the four common scales of measurement: nominal, ordinal, interval and ratio. Each scale of measurement has properties that determine how to properly analyse the data.What are the problems in psychological measurement? ›
There are three major issues in psychological testing: reliability, validity and bias. Reliability is when a test consistently delivers the same results, either over time or across psychologists. Validity is when a test accurately measures what it's supposed to measure.What are 4 levels of measurement with examples? ›
Nominal: the data can only be categorized. Ordinal: the data can be categorized and ranked. Interval: the data can be categorized and ranked, and evenly spaced. Ratio: the data can be categorized, ranked, evenly spaced and has a natural zero.What is measurement in short answer? ›
Measurement is a comparison of an unknown quantity with a known fixed quantity of the same kind. The value obtained on measuring a quantity is called its magnitude. The magnitude of a quantity is expressed in numbers and in its unit.What is measurement in simple words? ›
ˈmāzh- : the act or process of measuring. : a figure, extent, or amount obtained by measuring. 3. : a system of measures.What is used to measure psychological variables? ›
Psychological tests (also known as mental measurements, psychological instruments, psychometric tests, inventories, rating scales) are standardized measures of a particular psychological variable such as personality, intelligence, or emotional functioning.What are 4 levels of measurement? ›
Levels of Measurement. Nominal, Ordinal, Interval and Ratio.