MCQs Flashcards
For questions 1 to 3, classify whether each variable is nominal or continuous:
Age
Continous
For questions 1 to 3, classify whether each variable is nominal or continuous:
Gender
Nominal
For questions 1 to 3, classify whether each variable is nominal or continuous:
Height
Continous
Which of the following best describes a confounding variable?
A variable that affects the outcome being measured as well as, or instead of, the independent variable
If a test is valid, what does this mean?
The test measures what it claims to measure
A variable that measures the effect that manipulating another variable has is known as:
A dependent variable
The discrepancy between the numbers used to represent something that we are trying to measure and the actual value of what we are measuring is called:
Measurement error
A frequency distribution in which low scores are most frequent (i.e. bars on the graph are highest on the left hand side) is said to be:
Positively skewed
Which of the following is designed to compensate for practice effects?
Counterbalancing
Variation due to variables that have not been measured is known as:
Unsystematic variation
The purpose of a control condition is to:
Allow inferences about cause
If the scores on a test have a mean of 26 and a standard deviation of 4, what is the z-score for a score of 18?
-2
The standard deviation is the square root of the:
variance
Complete the following sentence:
A large standard deviation (relative to the value of the mean itself):
indicates that the data points are distant from the mean (i.e. the mean is a poor fit of the data)
The probability is p = 0.80 that a patient with a certain disease will be successfully treated with a new medical treatment. Suppose that the treatment is used on 40 patients. What is the “expected value” of the number of patients who are successfully treated? - (2)
32
simply multiply each value of the random variable by its probability and add the products.
Which of these variables would be considered not to have met the assumptions of parametric tests based on the normal distribution?
Hint: Many statistical tests rely on having data measured at the interval level.) - (2)
Gender
The correct answer is c) Gender. This is because this variable is not measured at the interval level and would not be normally distributed.
The test statistics we use to assess a linear model are usually _______ based on the normal distribution.
parametric tests
Which of the following is not an assumption of the general linear model?
Dependence
Looking at the table below, which of the following statements is the most accurate?
For the number of hours spent practising, there is not an issue with kurtosis
How many outliers are in this graph in total?
What does this table of data show?
- Both normality tests for female and male are non significant (p = 0.200) so this means the assumption of normality is satisfied
List all the elements of this boxplot - (7)
- IQR
- Minium
- 1st Quartile
- Median
- 3rd Quarticle
- Maximum
- Outlier
The normality tests are dependent on
sample size you have
What is the purpose of a control condition?
Allow inferences about case
What statement is the most accurate?
For the number of hours spent practicing there is not an issue with kurtosis
Which of the following is NOT an assumption of the General Linear Model?
Dependence - residuals should be indepndent (no correlation of consecutive residuals in same data)
A variable that measures the effect that manipulating another variable has is known as…
DV
Using the data provided, how would you summarise skew?
A: The data has issue with positive skew
What is the median number of bullt shot by partner by females? (2DP)
C: 67.00
What descriptive statistic does the red arrow represent?
A: Interquartile range (IQR)
What is the mean for “Males”? - (2DP)
B. 27.29
What is the standard deviation for “Females”? - 2DP
12.20
What are the respective standard error of mean for “Females” and “Males”? - 2DP
3.26 & 3.42
What is the correct interpretation of the data?
Males performed better than females in the reward condition, and females performed better than males in the indifferent condition. Regarding the confidence intervals, there was a small degree of overlap between males and females for the reward and indifferent conditions, and a large degree of overlap between males and females for the punish condition.
What is correct interpretation of data, mean represents anxiety
Mean anxiety scores were reduced across the three time points, and there was a slight acceleration in this reduction between the middle and end of the course.
Children can learn a second language faster before the age of 7’. Is this statement
one-tailed hypothesis - states direction of effect
Which of the following is true about a 95% confidence interval of the mean - (2)
95 out of 100 confidence intervals will contain thepopulation mean -
f we’dcollected 100 samples, calculatedthe mean and then calculated aconfidence interval for that mean,then for 95 of these samples theconfidence intervals weconstructed would contain the truevalue of the mean in thepopulation
What does a significant test statistic tell us?
That the test statistic is larger than we wouldexpect if there were no effect in the populatio
Of what is p the probability?
p is the probability of observing a test statistic atleast as big as the one we have if there were noeffect in the population (i.e., the null hypothesiswere true)
A Type I error occurs when:
We conclude that there is an effect in thepopulation when in fact there is not
Power is the ability of a test to detect an effect given that an effect of a certainsize exists in a population.
TRUE or False
True
We can use power to determine how large a sample is required to detect aneffect of a certain size.
TRUE OR FALSE
True
Power is linked to the probability of making a Type II error.
TRUE OR FALSE?
TRUE
The power of a test is the probability that a given test is reliable and valid.
TRUE OR FALSE
False
What is the relationship between sample size and the standard error of the mean?
he standard error decreases as the sample sizeincreases
What is the null hypothesis for the following question: Is there a relationship betweenheart rate and the number of cups of coffee drunk within the last 4 hours?
There will be no relationship between heart rateand the number of cups of coffee drunk within thelast 4 hours
A Type II error occurs when
We conclude that there is not an effect in thepopulation when in fact there is
n general, as the sample size (N) increases:
The confidence interval gets narrower
Which of the following best describes the relationship between sample size andsignificance testing?
n large samples even small effects can bedeemed ‘significant’
The assumption of homogeneity of variance is met when - (2)
The variances in different groups areapproximately equal
Yes, this is correct. To make sureour estimates of the parametersthat define our model andsignificance tests are accurate wehave to assume homoscedasticity(also known as homogeneity ofvariance)
