Scientific Inquiry And Research Methodology Mastery Exam Practice Tests

Question 1

A researcher proposes a hypothesis that the average reaction time $\mu$ of a group is equal to $250$ ms. If the observed data yields a p-value of $0.03$ given the null hypothesis $H_0: \mu = 250$, which conclusion follows the principle of falsifiability?

Accepted Answer

Reject the null hypothesis at the $\alpha = 0.05$ significance level.

Answer

Accept the null hypothesis because the reaction time is close to 250 ms.

Answer

Conclude that the theory is proven true for all populations.

Answer

Ignore the p-value as it does not provide absolute certainty.

Question 2

A study measures anxiety using a scale where the observed score $X$ is defined as $X = T + E$, where $T$ is the true score and $E$ is random error. If the variance of the true scores is $\sigma^2_T = 16$ and the variance of the error is $\sigma^2_E = 4$, calculate the reliability coefficient $\rho_{XX'}$ using the formula $\rho_{XX'} = \frac{\sigma^2_T}{\sigma^2_T + \sigma^2_E}$.

Accepted Answer

0.8

Question 3

Which of the following scenarios demonstrate a threat to the validity of a measurement tool?

Answer

A scale designed to measure mathematical aptitude actually measures reading comprehension speed.

Answer

A survey intended to measure depression consistently yields high scores for individuals who are not depressed.

Answer

A thermometer that consistently reads $2$ degrees higher than the actual temperature but does so every time.

Answer

A stopwatch that provides the exact same time reading for the same event across ten trials.

Question 4

If a measurement tool has a reliability coefficient of $\rho_{XX'} = 0.95$, it is mathematically impossible for the tool to have low validity.

Accepted Answer

False

Answer

True

Question 5

In a study, the correlation between a new test $X$ and a gold-standard criterion $Y$ is $r_{XY} = 0.6$. If the reliability of the test is $\rho_{XX'} = 0.8$, calculate the corrected validity coefficient using the formula $r_{corrected} = \frac{r_{XY}}{\sqrt{\rho_{XX'}}}$.

Accepted Answer

0.67

Question 6

A researcher claims that a specific intervention increases IQ scores by exactly $10$ points. To evaluate this claim using scientific rigor, which approach is most appropriate?

Accepted Answer

Design an experiment with a control group and calculate the effect size $d = \frac{\mu_1 - \mu_2}{\sigma}$.

Answer

Collect testimonials from participants who felt smarter after the intervention.

Answer

Assume the claim is true because it was published in a popular magazine.

Answer

Replicate the study only once and accept the result if it aligns with the hypothesis.

Question 7

The principle of falsifiability suggests that for a theory to be scientific, there must be a conceivable observation that could prove the theory false.

Accepted Answer

True

Answer

False

Question 8

A researcher estimates a population proportion $p$ using a sample size $n = 400$. If the observed count of the target behavior is $x = 120$, calculate the margin of error at a 95% confidence level ($z = 1.96$) using the formula $ME = z \sqrt{\frac{\hat{p}(1-\hat{p})}{n}}$.

Accepted Answer

0.048

Answer

0.024

Answer

0.096

Answer

0.120

Question 9

In a study of 1,000 participants, the researcher finds that the probability of a specific health outcome is $P(A) = 0.15$. If the sample is not representative and the true population probability is $P(A)_{true} = 0.20$, calculate the absolute bias defined as $|P(A) - P(A)_{true}|$.

Accepted Answer

0.05

Question 10

If the Pearson correlation coefficient $r$ between two variables $X$ and $Y$ is $0.85$, then $85\%$ of the variance in $Y$ is explained by $X$.

Accepted Answer

False

Answer

True

Question 11

Given two variables $X$ and $Y$ with covariance $Cov(X, Y) = 12$, standard deviation $\sigma_X = 4$, and standard deviation $\sigma_Y = 5$, calculate the correlation coefficient $\rho = \frac{Cov(X, Y)}{\sigma_X \sigma_Y}$.

Accepted Answer

0.6

Answer

0.3

Answer

0.5

Answer

0.8

Question 12

Which of the following conditions are necessary to establish a causal claim between an independent variable $X$ and a dependent variable $Y$?

Answer

Manipulation of the independent variable

Answer

Random assignment of participants

Answer

Control of extraneous variables

Answer

High correlation coefficient $r > 0.9$

Question 13

In an experiment, the mean of the control group is $\mu_1 = 50$ and the mean of the treatment group is $\mu_2 = 65$. If the pooled standard deviation is $s_p = 10$, calculate Cohen's $d = \frac{\mu_2 - \mu_1}{s_p}$.

Accepted Answer

1.5

Question 14

If a researcher uses random assignment to split 100 participants into two groups of 50, and the probability of any individual being assigned to the treatment group is $P = 0.5$, what is the expected number of participants in the treatment group?

Accepted Answer

50

Answer

25

Answer

75

Answer

100

Question 15

A researcher is evaluating a new teaching method in two classrooms. Class A uses the new method, while Class B continues with the traditional method. If the researcher calculates the effect size $d$ using the formula $d = \frac{\bar{x}_1 - \bar{x}_2}{s_p}$, where $s_p = \sqrt{\frac{(n_1-1)s_1^2 + (n_2-1)s_2^2}{n_1+n_2-2}}$, and finds $d = 0.85$, which design is most appropriate if random assignment of students was not possible due to school policy?

Accepted Answer

Quasi-experimental design

Answer

Experimental design

Answer

Single-subject design

Answer

Correlational design

Question 16

In a single-subject A-B-A design, the baseline phase (A) has a mean performance of $\mu_A = 10$ and the intervention phase (B) has a mean of $\mu_B = 25$. Calculate the percentage of change in performance from the baseline to the intervention phase using the formula $P = \frac{\mu_B - \mu_A}{\mu_A} 	imes 100$.

Accepted Answer

150%

Question 17

Which of the following scenarios represent potential threats to internal validity that a researcher must mitigate to ensure ethical and accurate results?

Answer

The researcher unconsciously provides subtle cues to participants, influencing their responses.

Answer

Participants modify their behavior because they are aware they are being observed in a study.

Answer

The sample size is too large to conduct a t-test.

Answer

The study uses a randomized control group.

Question 18

In a study where the trade-off between internal and external validity is modeled by the function $V(c) = -c^2 + 10c$, where $c$ represents the level of experimental control, the optimal level of control $c$ is found at $c = 5$.

Accepted Answer

True

Answer

False

Question 19

If a researcher determines that the probability of a Type I error is $\alpha = 0.05$ and the power of the study is $1 - \beta = 0.80$, what is the probability of a Type II error ($\beta$)?

Accepted Answer

Option A

Answer

Option B

Answer

Option C

Answer

Option D

Question 20

A researcher conducts a study with a cost function $C(n) = 50n + 200$, where $n$ is the number of participants. If the budget is €1200, solve for the maximum number of participants $n$ the researcher can afford.

Accepted Answer

20

Scientific Inquiry And Research Methodology Mastery Exam Practice Tests

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Scientific Inquiry and Research Methodology Mastery Exam

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