NUFD404 EXAM 1
Power analysis is based on the relationships between which factors?
all of the above
One disadvantage of randomized controlled trials is that they:
are expensive and time-consuming
negative correlation
as one variable increases, the other decreases
In a(n) ___________ relationship, two variables are statistically related.
associative
Pretest data, sometimes called ________ data, is useful along with demographic data to evaluate whether randomization really produced equivalent groups.
baseline
In a _______________, researchers test new treatments, drugs, or medical devices with human participants to assess efficacy and safety.
clinical trial
Which design can be used to examine differences in variables in two or more groups that occur naturally in a setting when variables are not manipulated?
comparative design
In a crossover design, each participant acts as his or her own control, therefore minimizing the effect of:
confounding variables
Which type of validity measures how well an instrument measures the concept it is intended to measure?
construct
A sample of 150 adolescents was obtained at 3 fast-food restaurants. Which sampling method was used?
convenience sampling
Which type of validity measures how well an instrument stacks up against another instrument or predicts something?
criterion
Researchers collected data for their study on nutrition and renal disease at one time early in January. What type of study is it?
cross- sectional
Researchers collected data for their study on nutrition and renal disease at one time early in January. What type of study is it?
cross-sectional
A study determined that 66% of American adults are either overweight or obese. Which type of research design was used?
descriptive
Which type of design does not have an intervention?
descriptive
A study showed that 50% of older adults read and used nutrition label information. Which study design was used?
descriptive cross-sectional design
Descriptive designs:
designs that provide a picture of a situation as it is naturally happening without manipulation of any of the variables
Interpretation of the data generated by a study is put into which section?
discussion
Which section of a research study compares results to previous studies?
discussion
A type of research design characterized by extensive control of the intervention and setting as well as randomization is which design?
experimental
Which of these designs may have an intervention?
experimental and quasi-experimental
Which of the following designs is most useful with research questions about therapy?
experimental design
In epidemiology, a risk factor is called a(n):
exposure
A control group may not receive standard or usual health care in a study.
false
A correlation coefficient of 0.6 is considered strong.
false
Correlation coefficients are not affected by outliers.
false
High bias in a study means high validity.
false
In a randomized controlled trial, threats to external validity are minimized when the setting is very controlled.
false
Validity of an instrument refers to whether the instrument measures consistently under similar circumstances.
false
Which of the following is NOT a threat to internal validity?
fishing
Cronbach's alpha coefficient is used to test which of the following?
internal consistency reliability
If the participants in a study were allowed to select either the experimental or control group in a study on exercise, this would be a threat to __________________.
internal validity
A study observed and measured fruit and vegetable consumption 5 times before and 5 times after a group of WIC participants completed online modules on the benefits of eating more fruits and vegetables. Which study design was used?
interrupted time series design
In a(n) ________ study, participants are observed and measurements taken at different points in time.
longitudinal
Which of the following is NOT a common extraneous variable in nutrition studies.
low sodium diet
Power analysis is used to determine:
minimum sample size
A positive correlation means that the two variables:
move in the same direction
Which of the following are not considered primary research?
narrative reviews and systematic reviews
A study in which participants were not randomly assigned to groups assessed the effects of an intervention. Which study design was used?
nonequivalent control group design
To show good inter-rater reliability, the intraclass correlation coefficient should be:
not .50
Factors outside of the variables being studied that might influence the outcome of a study are:
not a form of bias
Which of the following is NOT a characteristic of a randomized controlled trial?
not an intervention
Advantages of cross-sectional studies include that they:
not are relatively inexpensive and can estimate prevalence of an outcome
A hypothesis stating that a relationship exists but not predicting the exact nature of the relationship is referred to as a(n) ________ hypothesis.
not associative
A sample of 250 RDNs was randomly selected from a list of all RDNs in the state of California for a California policy study. Which sampling method was used?
not cluster random sampling
The extent to which the independent variable, rather than some extraneous variable(s), actually caused the outcome of the study is referred to as:
not construct validity
In an experimental research study, the independent variable is:
not controlled
Which research design generally has more internal validity?
not correlational design, experimental design, and quasi-experimental design
If an instrument correlates well with another previously established and valid instrument, this is referred to as:
not criterion validity
In a study examining the effect of vitamin D supplements on bone density in women, the age of the participants would be which type of variable?
not dependent
A study was conducted to examine the effectiveness of a new drug to lower LDL levels, and participants were randomized to the experimental or control group. Which type of research design was used?
not descriptive
Which of the following designs is most useful with research questions on treatment or therapy?
not descriptive correlational design
A study looked at how many children skipped lunch in an urban area in 2010 and again in 2015. Which study design was used?
not descriptive cross sectional design
The Diabetes Risk Score is a reliable and validated instrument being used in a study, which strengthens which type of validity?
not internal validity
A description of the study population and setting is put into which section of a research paper?
not intro
Which of the following designs is most useful in the evaluation of community interventions when randomized controlled trials are impractical and too expensive?
not nonequivalent control design group
The probability of correctly rejecting the null hypothesis is called:
not power
A group of researchers did a study on children's eating habits using data from NHANES. This is an example of:
not primary analysis
A researcher tested an instrument for reliability and validity. This is an example of:
not primary data
For a study on nutrition and stage IV pressure ulcers, a sample of 36 home health patients were asked to participate because they had stage IV pressure ulcers. Which sampling method was used?
not quota sampling
Systematic errors that are NOT due to chance or normal variability are referred to as:
not random errors
Which of the following designs is most useful when a researcher thinks the outcomes could be biased by exposure to the pretest?
not randomized controlled trial
A sample of 400 people with diabetes was obtained by asking 20 diabetes care managers in 20 randomly selected large urban hospitals to randomly choose 20 Type 2 diabetes adult patients. Which sampling method was used?
not simple random sampling
A measure that has 65% ______________ will screen or diagnose correctly 65 out of every 100 people who have the condition.
not specificity
The ability of a study to detect statistically significant differences or relationships in the groups when they really do exist is known as:
not statistical significance
Which statistical procedure is used to measure and describe the relationship between 2 variables that are continuous and normally distributed?
not t-test
To measure diet quality in a study, researchers have to decide on the specific way the variable will be measured, which is referred to as the ___________ definition.
not theoretical
The hypothesis stating that no relationships exist among the variables being studied is the:
null hypothesis
Epidemiologic designs are most often:
observational
In a cross-sectional study, data is gathered at:
only one point in time
Intention-to-treat analysis is used to prevent biases due to:
participant attrition
Which of the following is NOT put in the Methods section of a research paper?
participant demographics
In a single-blind study, which group is blinded?
participants
Army personnel were asked to complete a survey about their dietary and nutritional supplement use as well as their personal characteristics such as amount of time spent in physical activity. The researchers examined the personal characteristics that would predict use of dietary and nutritional supplement use. Which type of research design was used?
predictive correlational
In the introduction of a research article, the _____________ identifies the specific gap or dilemma into which the researchers want to gain further insight.
problem statement
basic research
pure research that aims to confirm an existing theory or to learn more about a concept
A study was conducted to determine the effect of vitamin supplements on growth in infants with failure to thrive. One pediatric office supplied participants for the experimental group, and another pediatric office supplied participants for the control group. Which type of research design was used?
quasi-experimental
Which statistical technique is used in predictive correlational designs to find out how much influence is exerted by the independent variable(s) on the dependent variable?
regression
If the P-value of a t-test is less than 0.05, the researchers should _________ .
reject the null hypothesis
Which of the following appropriately describe this hypothesis: We hypothesized that parental feeding strategies aimed at increasing children's familiarity with a novel food would result in a higher frequency of children consuming the novel food.
research hypothesis and causal hypothesis
A clear, concise statement of the specific focus on the study is referred to as the:
research objective
translational research
research that uses knowledge obtained from basic research for developing and testing solutions to real-world problems ex- an example is the treatment for a certain virus may be effective in a clinical trial but is it also effective in large scale populations that need it?
A measure with 81% __________ means it finds every 81 out of 100 people who do not have the condition.
specificity
An error that occurs consistently in one direction, such as a scale that weighs everyone two pounds more than their true weight, is known as a:
systematic error and bias
When respondents take the same test at two different times to see how consistent their answers are, this is referred to as:
test-restest reliability
Models may draw on a number of __________ to help explain a particular problem in a certain construct.
theories
A construct is usually more complex than a concept.
true
A nonequivalent control group design is not as strong in controlling for threats to internal and external validity as is a true experimental design.
true
Descriptive correlational studies can lay the groundwork for testing a hypothesis in a later study.
true
Epidemiologists, sometimes called disease detectives, try to connect the dots between exposures and health outcomes.
true
In addition to knowing about the statistical significance of your data, it is important to know about effect size, the strength of the relationship between your variables.
true
Most randomized controlled trials use a pretest-posttest design.
true
The Results section is limited to the actual data generated by the study.
true
When the control group receives no treatment, you will see a greater difference between the groups than with usual care or some treatment.
true
You did not reject the null hypothesis. It is possible that you made a:
type II error
A period of time in a study during which subjects receive no treatment and the effects of a previous treatment are cleared from the subject's system is called the:
washout period
The closer a correlation coefficient is to _____, the stronger the relationship between the variables.
+1 and -1
Which of the following correlation coefficients represents the strongest relationship?
-.83
In a 4 x 2 factorial design, how many experimental conditions are there?
8
