Which of the following statements descrbes best the characteristics of the one-tailed and two-tailed tests in statistical hypothesis testing?

Question

BlackTom AI · Accepted Answer

Topic focus: the contrast between one-tailed and two-tailed tests in hypothesis testing, and when each is appropriate.
Option 1: 'The decision to choose a one-tailed vs. two-tailed test should be made and changed depending on the data to ensure that the research hypotheses are supported as much as possible' This suggests making or changing the test type after seeing the data, which biases the test and inflates Type I error. In proper practice, the decision should be made a priori (before data analysis) based on theory or hypotheses, not adjusted to push findings in a desired direction.
Option 2: 'A one-tailed test is used when the hypothesis predicts the direction of the effect, while a two-tailed test does not specify the direction' This captures the standard distinction: a one-tailed test tests a specific directional alternative, whereas a two-tailed test tests for any difference in either direction, reflecting a nondirectional hypothesis. It aligns with conventional statistical reasoning and is correct when the hypothesis specifies direction.
Option 3: 'A one-tailed test is preferred when the research question is unclear, while a two-tailed test is more specific' This statement reverses typical practice. If the question is unclear, analysts often use a two-tailed test as a more conservative approach because it does not assume a direction. Labeling the one-tailed test as preferred for unclear questions is misleading and incorrect.
Option 4: 'Usually the one-tailed test is the preferred method over the two-tailed test as the use of the one-tailed test requires strong theoretical/empirical reasons' While it is true that one-tailed tests require justification, it is not accurate to claim they are usually preferred. In many fields, two-tailed tests are the default unless a strong, a priori directional hypothesis exists. The statement overgeneralizes current practice and understates the need for justification and the potential bias.
Overall, only Option 2 correctly describes the intended relationship between hypothesis direction and the corresponding test type, while the other options contain misconceptions about when and how to choose one-tailed versus two-tailed tests.

2025/26/1 PSYB19-104 1 - Basics of Research Methods Exam (16 December, 11:00)

Which of the following statements descrbes best the characteristics of the one-tailed and two-tailed tests in statistical hypothesis testing?

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Similar Questions

Which one is true?

For an upper-tail hypotheses about a population mean with σ known and α=5%, which one is the rejection region?

For a given sample, the P-value for upper tail test is x, and the P-value for two-tailed test is y, then

For a two-tailed hypothesis test with a test statistic value of z = 2.09, the p-value is _____.

For a sample size of 30, changing from using the t distribution to using the standard normal distribution in a hypothesis test _____.

Exhibit 9-5 n = 16 H0: μ ≥ 80 = 75.607 Ha: μ < 80 σ = 8.6 Assume the population is normally distributed. Refer to Exhibit 9-5. The p-value is equal to _____.

Exhibit 9-1 Refer to Exhibit 9-1. If the test is done at a .01 level of significance, the null hypothesis should _____.

What conclusion for a test would correctly detect a difference between the actual parameter and the hypothesized value for the parameter? c08.p089.q0008

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2025/26/1 PSYB19-104 1 - Basics of Research Methods Exam (16 December, 11:00)

Which of the following statements descrbes best the characteristics of the one-tailed and two-tailed tests in statistical hypothesis testing?

View Explanation

Log in for full answers

Similar Questions

Which one is true?

For an upper-tail hypotheses about a population mean with σ known and α=5%, which one is the rejection region?

For a given sample, the P-value for upper tail test is x, and the P-value for two-tailed test is y, then

For a two-tailed hypothesis test with a test statistic value of z = 2.09, the p-value is _____.

For a sample size of 30, changing from using the t distribution to using the standard normal distribution in a hypothesis test _____.

Exhibit 9-5 n = 16 H0: μ ≥ 80 = 75.607 Ha: μ < 80 σ = 8.6 Assume the population is normally distributed. Refer to Exhibit 9-5. The p-value is equal to _____.

Exhibit 9-1 ​ ​ Refer to Exhibit 9-1. If the test is done at a .01 level of significance, the null hypothesis should _____.

What conclusion for a test would correctly detect a difference between the actual parameter and the hypothesized value for the parameter? c08.p089.q0008

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Exhibit 9-1 Refer to Exhibit 9-1. If the test is done at a .01 level of significance, the null hypothesis should _____.