Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [one-tailed-test]

28 questions
7
votes
2 answers

What is wrong with one tailed z-tests for a proportion?

After answering How to analyze observed vs expected when expected is just a proportion? by suggesting that the OP uses a one tail Z-test for their proportion data, I got into a debate in the comments with another user to which their point is lost on…
user64106
7
votes
2 answers

Interpreting one- and two-tailed tests

How do you report results that give you a p-value of 0.08 for a two-tailed test and a p-value of 0.04 for a one-tailed test? Generalizing the issue, if you obtain a p-value between 0.05 and 0.9999 from a two-tailed test, does it make sense to…
Rudolph
  • 91
  • 1
  • 4
4
votes
1 answer

Paired sample: Two-tailed and one-tailed

In the book: "Essentials of Statistics for Business & Economics", the part about matched sample t-test, I see that it uses the two-tailed t-stat. However, instead of stating the null and alternate hypotheses as "equal 0" and "not equal 0", it sets:…
TimD
  • 41
  • 1
2
votes
1 answer

alpha value for one tail test and two tail test in t-test

I am using t-test with confidence interval of 95% so my significance level is p = 0.05 Now if I am using one-tail test then all alpha will be alloted to one-tail. let the left tail. so the alpha value in t-table with respect to one-tail should be…
Raj_Ame09
  • 23
  • 5
2
votes
0 answers

Most data-efficient way to "pick the best tail and test it"?

Before I begin, I would like to note that I am familiar with the ordinary debate between one-tailed and two-tailed tests and the gazillions of questions already on Cross Validated about the matter. Essentially, though, it seems that there is no…
Him
  • 2,027
  • 10
  • 25
2
votes
0 answers

Probabilities : One-tailed test implication for two-tailed test?

I had an exam with a question (multiple choice) that had this question: If I perform a test with a significance level of alpha = 0.05 and reject H0 for a one-sided test, it means that: A) I reject H0 for a bilateral test with alpha = 0,1 B) I reject…
M. Warzowski
  • 21
  • 2
2
votes
0 answers

Adjusting P-Values of one-tailed tests

I am running a large number of two-sample Wilcox tests and using Benjamini, Hochberg, and Yekutieli method to adjust the p-values. The issue is that when I conduct a one-tailed test, the p-values before the adjustment satisfy p-value(>) +…
S.K.
  • 21
  • 1
1
vote
0 answers

Hypothesis testing with one tailed test

I have a model: $$Y=\beta_0+\beta_1x_1+\beta_2x_2+\beta_3X_3+\beta_4x_4$$ and I want to test these two hypotheses: $$H_0: \beta_1>-3 \qquad H_a: \beta_1<-3$$ So if I conduct a one-sided test at the $\alpha=1\%$ significance level, the value of the…
user8000
  • 11
  • 3
1
vote
1 answer

Question about the p-value in one-sided hypothesis testing compared to two-sided hypothesis testing

I am watching an online tutorial about one-sided hypothesis testing versus two-sided hypothesis testing. This tutorial discusses when you should use one-sided hypothesis testing compared to two-sided hypothesis testing. One of the things mentioned…
ceno980
  • 173
  • 6
1
vote
1 answer

Can I test this hypothesis with a one-tailed test?

A student wants to investigate whether people from northern USA are more severely affected by winter depression ("seasonal affective disorder") than people from southern USA, using a questionnaire. I think this is a one tail test: H0: u=0 H1: u >…
Okidoki
  • 11
  • 1
1
vote
0 answers

How to calculate/interpret P-value in one versus two-tailed tests?

I am conducting an ordinal logistic regression and my alternative hypothesis is one-directional (I predict that my independent variable positively affects my dependent variable) and my null hypothesis is that my independent variable does not…
Joey
  • 11
  • 1
1
vote
1 answer

Do you correct for multiple comparisons in one-tailed t-tests?

I'm collection reaction time (RT) data on participants from the same group tested in 4 conditions (A, B, C, D). Since I have a directional hypothesis (RT of A>B>C>D), I'm using three one-tailed t-test (A vs B, B vs C, C vs D). My question is: if I'm…
giorgio-p
  • 47
  • 4
1
vote
1 answer

Regarding the calculation of $p$ values in one tailed tests

In two tailed hypothesis tests, under symmetric sampling distributions, it is necessary to double the $p$-value, which makes sense from the definition of a $p$-value, given that it is equal to the conditional probability that we obtain test…
Luis Sierra
  • 113
  • 4
1
vote
0 answers

How are critical values for correlation coefficients (product moment correlation coefficient) calculated?

I have a fairly basic understanding of statistics. I've been learning about measuring correlation using product moment correlation coefficients (I think they're also called Pearson correlation coefficients). I was doing a simple one-tailed…
Henry
  • 111
  • 4
1
vote
0 answers

When to use one tailed or two tailed tests for power analysis?

Is it ok to choose one tailed test if it is assumed that a certain drug is going to reduce metastatic tumor?
Lily
  • 25
  • 2
1
2