All Questions
13 questions
6
votes
3
answers
427
views
The rationale for when significance or null hypothesis testing is needed
Why do people sometimes claim that an effect is so huge and "obvious" that it does not warrant any inferential statistics calculation, even though the sample size is not large?
This is ...
- 175
0
votes
1
answer
41
views
Within subject experiments done by (some) Psychologists
Thanks in advance for any responses or resources you can link me to.
I've had more of an Econ/Stats training and recently I've been working with some people who have a Psych background at work.
They ...
3
votes
1
answer
80
views
How do data/observations themselves contribute to our ability to make determinations of whether a hypothesis is true or false?
Let's say that I have a hypothesis, and I'm trying to determine whether the hypothesis is true or false. If I remember correctly, in statistics, the standard philosophical view is that, technically, ...
- 2,204
0
votes
0
answers
25
views
What is the proper power analysis approach in this A/B test
This may be a dumb question but will ask here:
We launched an experiment that has 3 groups Treatment A vs Treatment B vs Control measuring a metric clicks per user.
We did our power analysis before we ...
- 71
2
votes
1
answer
97
views
How to best evaluate A/B Test result for statistical and practical significance holistically?
I am working on evaluating an experiment or A/B test but I am fairly new to it. In that process, I am trying to interpret which post-test metrics are significant and the methodology to decide that. ...
- 21
0
votes
1
answer
37
views
Which statistical analysis/design to use on clinical hospital data with varying amounts of available data for each patient?
We are currently working in our local hospital on a paper about the influence of the nephrologist on patients with kidney failure.
We are aiming to look at a couple of clinical (laboratory) outcomes ...
- 3
1
vote
0
answers
360
views
Making one-sided conclusions from two-sided tests
I'm reading Montgomery's Design and Analysis of Experiments. On page 39, he rejected a two-sided $t$-test against the null hypothesis that modified formulation of some cement mortar doesn't change its ...
- 1,817
1
vote
0
answers
35
views
Experimental Design and Inference For Proportions
I have a specific example for an experimental design using a control/test group that I want to make inferences on. I want to test the completion rate for the same training program done online vs. ...
- 541
0
votes
1
answer
80
views
What criteria differentials an A/B/C/etc... test with a Multivariate test with respect to webpages?
I'm a software engineer with a weak background in probability and statistics. I want to determine whether the position and color of the "Purchase" buttons affects my conversion rate. I want to create ...
0
votes
1
answer
50
views
Fundamental question about applying Anova
I have a fundamental question about applying ANOVA.
Suppose we are testing 4 drugs which reduce blood pressure. Our experiment contains 4 drugs + 1 Placebo. We give these to 3 types of patients (...
- 3
4
votes
1
answer
1k
views
Random Effect Model
One factor random effect model:
$$y_{ij}=\mu+\tau_{i}+\epsilon_{ij}\quad i=1,2,\ldots,a;
j=1,2,\ldots,n$$
where,
$y_{ij}$ is the $j$th observation of $i$th treatment effect
$\mu$ is the overall ...
- 1,427
1
vote
0
answers
116
views
Computing the F-ratio under null hypothesis
Statistical model for a Completely Randomized Design:
$$y_{ij}=\mu+\tau_{i}+\epsilon_{ij}\quad i=1,2,\ldots,a;
j=1,2,\ldots,n$$
where,
$y_{ij}$ is the $j$th observation of $i$th treatment effect
$...
- 1,427
4
votes
4
answers
524
views
What if your randomly formed groups are clearly not similar?
What if, before you begin the data collection for an experiment, you randomly divide your subject pool into two (or more) groups. Before implementing the experimental manipulation you notice the ...
- 3,427