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  1. Miner

    Statistical test or method to analyse a change in a variable over time.

    You are correct. I wasn't certain how your data were collected. You can use a 1-way ANOVA to determine whether any changes among the three groups are significant.
  2. Miner

    Statistical test or method to analyse a change in a variable over time.

    One simple approach that you can try is to plot the time series (# people using food bank) on an individuals control chart. This is a technique developed in industrial statistics to determine whether a process is stable and predictable, or under the influence of outside causes. If your data...
  3. Miner

    How to do data analysis for Likert scale questions?

    I agree with you Greta. I periodically analyze survey data with sample sizes in the thousands. Two questions may have distributions that are very different visually, yet have the same median and mode while the mean reflects the visual differences. While the mean may be somewhat biased in the...
  4. Miner

    Minitab 17 Discrete X Discrete Y Question

    As previously stated, your model is fully saturated. There are only enough degrees of freedom to estimate 15 terms. Your main effects and all 2-way interactions total 15. You need at least one degree of freedom to estimate the error term for a significance test. The best way of doing that is...
  5. Miner

    Need help with the appropriate statistical method

    A 2 proportions test.
  6. Miner

    Three-way ANOVA?

    This does change it somewhat. It now appears to be a split plot repeated measures design. The whole plot is the starting level of nematode and has 5 replicates. The subplot is the cover crop/control and has 3 replicates. The repeated measures are the 4 times in which the nematode population...
  7. Miner

    Three-way ANOVA?

    This is a split plot design (first developed in agriculture!). The field locations form the whole plots and the treatment/control form the subplots. Counting the population 4 times are repeats.
  8. Miner

    Correlation

    What about using a cross correlation to determine whether one or more of the time series is a leading indicator for another?
  9. Miner

    Relationships change, why

    Satisfaction is situational and will inherently change. If you have not read about the Kano model, I highly recommend doing so. I won't go through everything in the article, but want to point out the following: People will typically express satisfaction/dissatisfaction only about performance...
  10. Miner

    Finding Correlations

    I performed the analysis in Minitab. Excel does not have the capability to perform a cluster analysis. You can generate the scatter plot in Excel using a scatter (X-Y) plot (see attached), but would need the output from other software.
  11. Miner

    Finding Correlations

    Sorry. I did not attach the correct (latest) file. Here it is. And your interpretation of the responses vs cluster membership is correct.
  12. Miner

    Finding Correlations

    After running a factor analysis, the 2 questions (tech savvy and rating design) consolidate to a single factor, the two questions (create new food and create new menus) consolidate to a second factor, and the question (edit existing) falls out as not significant. Using cluster observations and...
  13. Miner

    Linear Regression and normal distributed data

    Neither are required to be normal. It is the residuals that must be normal. See the following paper on this topic.
  14. Miner

    Test for pre vs post measures for multiple groups?

    You can also calculate the pre-post difference and run a 1-way ANOVA on the difference. Use Dunnett's post hoc test to compare differences to the control group.
  15. Miner

    correlations with likert data

    This may be related to the expectation that there is no measurement error variation in the independent variables in regression. Ordinal data obviously does have a great deal of uncertainty. However, there are regression methods that can deal with errors in variables, so it is not an...
  16. Miner

    Finding Correlations

    Factor analysis will help you condense the number of questions down into a smaller number of factors underlying the questions. Your data appear to condense to 2 factors of importance. You can also go directly into Cluster analysis. I recommend Cluster Observations. This should accomplish...
  17. Miner

    Two way anova and Bonferroni

    I would presume so. The issue raised would seem to be independent of the actual analysis method and focused on whether that method was used for data snooping vs. confirmation of an a priori theory.
  18. Miner

    Two way anova and Bonferroni

    Interesting discussion. It was very difficult to find anything on this topic as family-wise error rates are always discussed in the context of a 1-way ANOVA. However, I did find one article that supports your concern when an exploratory ANOVA is used without an a priori theory. The article...
  19. Miner

    Two way anova and Bonferroni

    Multiple comparisons of means only comes into play when you have more than two levels per treatment This is a common occurrence for a 1-way ANOVA, but is less common for k-way ANOVAs. k-way ANOVAs are typically used to analyze designed experiments which are most commonly 2^k designs with 2...
  20. Miner

    Please help me with the calculation of the overall survival rate.

    My experience with survival analysis is product related, so things are often done slightly different than in other disciplines. We usually have data that contains a mixture of failure modes (similar to combining the control and treatment groups above) and need to separate the mixture. Also...