Tagged Questions

4
votes
1answer
37 views

How to rank order performance of four systems using aggregates of pairwise assessments of system performance?

I am currently designing an experiment to evaluate 4 iterations of a system. As it is rather difficult for a human to judge the output of the system by assigning it a score or several scores, I plan ...
1
vote
0answers
61 views

Expected value of sums of squares of a blocking factor in a split plot design

How can we show that in a split plot design, the expected value of the sum-of-squares of the blocking factor has expected value equal to $k\sigma^2_{\text{block}} + \sigma^2_{\text{error}}$? I tried ...
1
vote
1answer
121 views

Compare means of two groups with a variable that has multiple sub-group

I was unable to understand how to compare multiple mean values in each group. Within the subgroup the mean values influence each other (If one changes, the other changes automatically). I collected ...
0
votes
0answers
60 views

Determine if a statistically significant preference exists

I'm trying to determine if there is any statistically significant preference for objects (other content, products, etc) rendered in a module in a web page. I'm trying to create a simple experiment to ...
0
votes
2answers
220 views

Testing statistical significance of male vs female enrolment preference percentages between two different fields of education

The problem I have is as follows. I have enrolment data describing the number of male and female preferences for two broad fields of education: i) Information Technology and ii) Engineering. The ...
2
votes
0answers
58 views

Conflicting Answers from Marketing Test: Both Answers are Statistically Significant

I'm running a marketing test comparing banner A against banner B against banner C. Each banner received >10million exposures and based on response rate we concluded early in the test that banners B ...
3
votes
4answers
223 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 ...
1
vote
0answers
107 views

Limitation on group size with non-parametric permutation tests

I would like to know if there is any limitation in the size of the groups when you are implementing non-parametric permutation tests. My case belongs to the realm of medical imaging. I am comparing ...
1
vote
1answer
92 views

Interpreting significant difference when additional data added

I have two questions on interpreting the statistical analysis of data collected from production runs to produce an experimental material. We made four production runs, with some changes in each run. ...
3
votes
1answer
297 views

Analysing data from non-equivalent groups in a quasi-experimental design

I am doing a research on two groups, one experimental and one control, which are not randomly selected. In fact the two groups are intact groups. The purpose is to find the effect of the number of ...
4
votes
3answers
480 views

Calculate number of needed simulations

First I have to apologize for any uncorrect naming or categorisation of my question, as I am an electrical engineer rather than a mathematican. I have a simulation that outputs for a given number of ...
1
vote
1answer
235 views

How to deal with a 2x2 experimental design if the dependent variable is dichotomous?

I am assessing the acceptability of a sentence in a within-subjects design with two crossed factors (type of sentence, missing word). After reading each sentence, the participants answer a simple ...
7
votes
1answer
287 views

Why is running split tests until statistically significant a “bad thing”? (Or is it?)

I read this article on "how not to run an A/B test". And I still don't understand what exactly the author's reasoning is. Can someone dumb it down for me? I think what it might be saying is that ...
2
votes
0answers
131 views

How to compare results from two groups?

I'm getting confused with the analysis of one of my experiments. Here is how the results look like. There were P participants in the experiments and they were split into two groups P1 and P2. Every ...
7
votes
1answer
115 views

Can someone help me understand what type of problem I am looking at? Not sure if this classifies as hypothesis-testing

Please pardon me if this question is not clear. I am not sure if I am using the right terminologies. I have conducted an experiment in different environments multiple times. So my data looks ...