experiment design

  1. S

    Statistical design problems

    Hello everyone! since I´m not the best when it comes to statistics, I hope to find some good input over here :)! I´m currently writing my Master-Thesis. I want to explore the influence of about 5 factors on one specific dependent variable which is assumed to influence the...
  2. S

    Statistical test for algorithm performance

    I am developing different algorithms for a class of optimization problems. I have several problem instances in this class (some from real applications, some randomly generated), which do not differ in terms of structure, but in terms of data. I would like to compare the performance of my...
  3. X

    Minimum control size for determining effectiveness of treatment

    So the following scenario I have a treatment that I know to be effective, but I want to determine precisely how effective it in a (large) group of individuals I'm dividing them in to a test group and a control group so I can compare the effect of the treatment However, I want to keep the...
  4. X

    Determining minimum control group size for purposes of verifying lift

    I have the following scenario: - We want to send out an email blast to existing members to promote an upsell. - We are quite positive the email blast will increase the number of upsells, but we are interested in determining by how much. - So we want to keep a control group for...
  5. M

    Dealing with a strong ordering effect

    Hello, I'm conducting a study in which people have to judge a perceptual effect (by rating it on a 10 point continous scale). I have three levels of this effect and there are two different contexts. There was a first study in which the order of the effects was randomized, but not the...
  6. G

    Feedback on Experiment: bosses and meetings

    As my context is rather specific, I'll try to write an analogy that sounds more natural and preserves all characteristics of the original problem. It goes like this: A certain company has around 2k employees. Some of these employees are bosses of other employees. An employee might have...
  7. C

    Dichotomizing continuous variables for an EXPERIMENT not a survey

    I am aware of the many issues/pitfalls with splitting continuous variables in survey research. Nothing I have read addresses whether doing so to create groups which will then be assigned to tx conditions in a field experiment is ok, or less bad. (or worse?) For example: Social Dominance and...
  8. rogojel

    Nested and crossed

    hi, I have the folowing design: Two paper suppliers, slips of paper and measurement points on each slip. For each supplier we take, say, 3 slips of paper and on each slip we define 6 measurement points. Each slip is painted (same paint, same machine, same operator) and gloss is measured in...
  9. V

    Experimental Design/Need help reviewing my answers

    I am having difficulties with questions below. I know I have a couple of them wrong, but I am not sure which one. I keep going over and over trying to figure out which one to change. :confused: Below are my answers in bold. Thank you Question 2 Jon believes that coursing...
  10. G

    Conceptual Question: Experiment where you analyze different skew between conditions.

    Hi all, I had a psychology stats exam yesterday and one question was: 'Present a hypothetical experimental question in which the main interest is the difference in the skew of the dependent variable for different experimental conditions.' I understand this to mean that you have two or...
  11. L

    matched pairs VS complete randomization - correspondence test housing market

    I work in experimental economics, labor and housing market. I am trying to answer the following question: why do researchers use matched pairs of applications in labor market correspondence tests (typically in hiring context), whereas they use a completely randomized approach in the housing...
  12. L

    Asking causal questions directly vs measuring variables in a survey

    Hi all, is it okay to ask causal questions like "Does A cause B?" directly as survey questions instead of asking question that measure A and B separately and then analyzing the correlation/causation between them? To explain: I have several hypotheses that look like "A causes B", say...
  13. C

    state reason for using one tail in the analysis of variance test ?

    I think in this way that since in anova we partition the total variability into various independent components , and since the Mean square of this components follow chi-square distribution, and since the ratio of two chi-square distribution follows F- distribution, and since F- distribution...
  14. C

    What is model adequacy checking in anova?

    In anova, we assume that the random error term \epsilon_{ij} is independent and identically distributed with mean 0 and variance \sigma^2 How can I check the normality assumption and independence assumption? Does model adequacy checking mean "Checking the normality assumption that...
  15. D

    Experiment design and analysis for e-commerce

    Hi i'm new to the forum and hopefully somebody wants to offer me a bit of advice. I'm carrying out a marketing choice experiment to estimate the effect sizes of copywriting new texts for our webshop. So to set up the experiement, i've made a webshop mockup with 4 similar products, one of...
  16. O

    How to minimize variability in order to design a valid pricing experiment?

    Good morning, I want to run a pricing experiment to see the change in the number of purchases (i.e.demand) in response to a 10% increase in price in a specific market for my product. I selected 2 markets with very similar characteristics, where one will get a treatment effect and the other...
  17. K

    GLM questions for landscape experiment

    I am analyzing bird count data from surveys conducted each week (from Nov-April, when bird foraging most active near breeding cycle) for 6 years in 9 large experimental plots that are split amongst 3 regions in the landscape (6 yrs x 3 regions x 3 plots/region). We are interested in comparing...
  18. K

    Nested ANOVA Experimental Design Help

    Hi, This is my first time posting here so apologies if my post is not appropriate. I am a masters student doing a project on evaluation of conditioning methods to prepare farmed abalone for the stress of live export. I am looking at whether holding time duration and the ozone levels of the...