week 3

Question 1

Define a construct

Answer 1

are hypothetical attributes or mechanisms that help explain and predict behavior in a theory

can not directly observed or measured , it is possible to observe and measure the behaviors associated with the construct

Question 2

Define a variable

Answer 2

characteristics or conditions that change or have different values for different individuals

Question 3

Identify examples of well defined and easily measured variables

Answer 3

to evaluate difference or changes in variables it is essential that we are able to measure them

easily measured variables: age, weight, height
abstract: intelligence

Question 4

Identify examples of variables are abstract

Answer 4

anxiety, intelligence

Question 5

Briefly explain what an operational definition is and why operational definitions are sometimes necessary.

Answer 5

is a procedure for measuring and defining a variable that cannot be observed or measured directly

necessary to convert an abstract variable into a concrete entity in order to be observed and studied

Question 6

operationally define Receptive vocabulary

Answer 6

Number of words recognized upon seeing them.
Ability to follow commands
Answer simple complex yes/no questions.
Open-ended questions after being read a story.
Ability to point to correct objects or pictures given an auditory command.

Question 7

operationally define expressive vocabulary

Answer 7

Count the amount of words spoken.

looking at a picture and describing what they see

Use a battery of expressive language assessments such as clinical evaluation of language fundamentals three, which measures phonological awareness, sentence structure, language content and memory, etc.

Question 8

operationally define Hoarseness

Answer 8

Clinician rating of hoarseness.
volume and pitch
vocal rating scale

Question 9

operationally define breathiness

Answer 9

Clinician rating

vocal rating scale

Question 10

[type of validity] is demonstrated when scores obtained from a new measure are directly related to scores obtained from an established measure of the same variable.

Answer 10

concurrent validity

Question 11

[type of validity] is demonstrated when scores obtained from a measure accurately predict behavior according to a theory.

Answer 11

predictive validity

Question 12

[type of validity] requires that the scores obtained from a measurement procedure behave exactly the same as the variable itself. This type of validity is based on many research studies that use the same measurement procedure and grows gradually as each new study contributes more evidence.

Answer 12

construct validity

Question 13

Define test-retest reliability

Answer 13

is established by comparing the scores obtained from two successive measurements of the same individuals and calculating a correlation between the two sets of scores

Question 14

Define inter-rater reliability

Answer 14

is a degree of agreement between two observers who simultaneously record measurements of behaviors

used when measurements are obtained by direct observation of behaviors

can be measured by computing the correlation between the score from the two observers

Question 15

What is a ceiling effect, and how can it be a problem?

Answer 15

ceiling effect is a sensitivity problem where the score obtained in a research study tend to cluster at one end of the measurement scale. For ceiling effect the range is restricted at the high end - it can’t go any higher

Question 16

What are demand characteristics, and how do they limit the validity of the measurements obtained in a research study?

Answer 16

demand characteristics refers to any of the potential cues or features of a study that 1) suggest to the participants what the purpose and hypothesis is and 2)influence the participants to respond or behave in a certain way

might limit the validity because participants who are aware they are being observed and measured may react in unpredictable or unnaturally thereby influencing the measurements they produce

Question 17

What is a population?

Answer 17

the larger group of interest. although the entire populaion usually does not partiicpate in a resaerch study the results from the study are gnerlaized to the entire population

Question 18

A speech-language pathologist has developed a new test for measuring receptive language and would like to determine the validity of the test. The new test and an established measure of receptive language are both administered to a sample of participants. Describe the pattern of results that would establish concurrent validity for the new test.

Answer 18

first must identify if the test is accurately measuring an individual’s receptive language ability

should compare the new test results with another test that is already used in the field to establish the accuracy/validity of the new test

identify the correlation of results between two tests: if positive, negative, or no correlation

Question 19

What are the four scales of measurement? Identify examples of each.

Answer 19

nominal – qualitative variables (gender, country, hair color)
ordinal – different names but organized sequentially (ranked data, educational level)
interval – organized sequentially, all intervals are same size, arbitrary 0 point (temperature in Fahrenheit)
ratio - organized sequentially, all intervals are same size, has true 0 point (# of stuttered syllables in 5 min conversation)

Question 20

Under what circumstances can a sample be biased?

Answer 20

selection bias occurs when participants or subjects are selected in a manner that increases the probability of obtaining a biased sample

a biased sample is a sample with different characteristics from those of the population

Question 21

identify the five research designs

Answer 21

descriptive, correlational, experimental, quasi-experimental, and nonexperimental

Question 22

name the broad research design category: Designs that examine individual variables (instead of relationships between variables)

Answer 22

descriptive research strategy: describes current state

Question 23

name the broad research design category: Designs that examine relationships between variables by measuring two (or more) variables for each participant

Answer 23

correlational: relationships between 2 variables (linear, curvilinear, positive, negative)

No causation
How does x compare to y
Good external validity
Low internal validity because can’t control

Question 24

name the broad research design category: Designs that examine relationships between variables by comparing two (or more) groups/sets of scores.

Answer 24

Experimental - highest level of research evidence; establishes causation using strict controls

quasi-experimental - can draw causation; less control than experimental like no randomization

Non experimental - looks at preexisting data, produces a description of the relationship b/w 2 variables but not causation

Question 25

Experimental research studies tend to have very (high/low) internal validity but often have relatively (high/low) external validity.

Answer 25

Experimental research studies tend to have very LOW internal validity but often have relatively HIGH external validity. Experimental research studies tend to have very HIGH internal validity but often have relatively LOW external validity.

Question 26

Under what circumstances can a sample be biased?

Answer 26

selection bias occurs when participants or subjects are selected in a manner that increases the probability of obtaining a biased sample a biased sample is a sample with different characteristics from those of the population usually n = 30, larger sample more representative selection bias

Question 27

what is the accessible population

Answer 27

a portion of the target population consisting of individuals who are accessible to be recruited as partipcants in the study

Question 28

what is a correlational research strategy

Answer 28

examines the relationship between 2 variables as they exist naturally for a set of indiivudals does not try to explain relationship between the 2 variables --> no cause and effect a research study that simply measures two variables for each individual and produces the kind of data in which each variable is measured with numerical scores

Question 29

what is an experimental research strategy

Answer 29

is intended to answer cause and effect questions about the relationship between two variables

Question 30

what is a quasi-experiemtnal research strategy

Answer 30

quasi-experimental: attempts to answer cause-effect but not as rigorously controlled

Question 31

Describe the concept of a study’s internal validity

Answer 31

a research study has internal validity if it produces a single unambiguous explanation for the relationship between two variables

Question 32

What are the common threats to internal validity?

Answer 32

is any factors that allows for an alternative explanation; any factors that generate doubts about the accuracy of the results or raises questions about the interpretation of the results -environmental variables -individual differences: characteristics differ from one person to another -time-related variables: history maturation – occurs over time/longitudinal instrumentation testing effects: fatigue, carry-over effects regression to the mean: the more you take a test, the more it will hover around the true score

Question 33

Describe the concept of a study’s external validity

Answer 33

refers to the extent to which we can generalize the results of a research study to people, settings, times, measures and characteristics other than those used in that study

Question 34

What are the common threats to external validity?

Answer 34

is any characteristic of a study that limits the ability to generalize the results from a research study threats include -- generalization from a sample to the general population - selection bias - volunteer bias generalization from one research study to another - novelty effect – reactions can vary - experimenter characteristics generalization from a research study to a real world situation - generalizability across measurements

Question 35

what is the goal of a research study?

Answer 35

is to measure a sample and then generalize the results to the population Experimental research studies tend to have very (high/low) internal validity but often have relatively (high/low) external validity.

Question 36

what is a correlational research strategy

Answer 36

examines the relationship between 2 variables as they exist naturally for a set of individuals does not try to explain relationship between the 2 variables Relationships between 2 variables (linear, curvilinear, positive, negative) Good external validity Low internal validity because can’t control

Question 37

what is nonexperimental research strategy

Answer 37

is intended to demonstrate a relationship between variables but it does not attempt to explain the relationship or establish causation Looks at preexisting data

Question 38

what is a descriptive research strategy

Answer 38

is intended to answer questions about the current state of individual variables for a specific group of individuals Example type: case study Weak internal validity - no control because looking at how something exists Weak external - not enough to generalize

Question 39

which 3 research strategies involve comparing groups of scores

Answer 39

experimental, quasi experimental, non experimental

Question 40

what is validity of measurement and what is validity of a reasearch study

Answer 40

validity of a measurement is refers to whether the procedure actually measures the variable that is claims to measure validity of a research study refers to the quality of the research process and the accuracy of the results

Question 41

what is validity of measurement and what is validity of a reasearch study

Answer 41

validity of a measurement is refers to whether the procedure actually measures the variable that is claims to measure validity of a research study refers to the quality of the research process and the accuracy of the results

Question 42

what is a confounding variable

Answer 42

is an extraneous variable that changes systematically along with the two variables being studies the key to achieving internal validity is to ensure that no extraneous variable is allowed to become a confounding variable

Question 43

what is a confounding variable

Answer 43

is an extraneous variable that changes systematically along with the two variables being studies - enviromental variables - individual differences - time-related variables the key to achieving internal validity is to ensure that no extraneous variable is allowed to become a confounding variable

Question 44

Compare and contrast interval and ratio scales.

Answer 44

ratio has a true zero temperature in C or F is interval because 0 is not the lowest point whereas temp in Kelvin is ratio bc 0 is the lowest possible

Question 45

What are the defining characteristics of a between-subjects design as compared to a within-subjects design?

Answer 45

between-subjects: compares scores different groups within-subjects: compares scores in two or more tx conditions by observing the same individual in each condition

Question 46

Explain the general advantages and disadvantages of a within-subjects design.

Answer 46

advantages: requires fewer participants eliminates/reduces individual difference confounding bc it’s the same participant disadvantages: performance is susceptible to time-related factors fatigue, sentimental changes btwn conditions, practice affects, attrition

Question 47

What are the two measures of variability?

Answer 47

variance: average squared distance of scores from mean standard deviation: avg distance of scores from mean easier to interpret bc in same units of measure