# Search results

1. ### What test should I do?

Is this everything the professor gave you? To decide on the test you need to explore the distributional properties of the data. And for that you need more information. For example, having a value for each participant would suffice. On the other hand, seeing only ranges and medians would not be...
2. ### Which Statistical Tool do I use?

Which optimization problem? Define "efficient". Again: what you are trying to achieve? What is the objective function (which you are optimizing)?
3. ### Which Statistical Tool do I use?

The answer depends on what you mean by "closest" and what you are trying to achieve. Please elaborate.
4. ### Correct for multiple comparisons with two time points and contingent relations

The number of sub-analyses is the number of p-values you generate. Does not matter where. If 1] for each of the correlations, you calculate a p-value to decide whether the correlation is significant and 2] all these correlations are used to shed light on the same research question sum all...
5. ### Correcting sample response data (Likert scale data)

Never throw away the data. Just recognize that the distribution is far from Gaussian and use appropriate statistical methods, nonparametric and parametric.
6. ### Correct for multiple comparisons with two time points and contingent relations

The number of comparisons is the number of p-values you generate for inference. It is never a good idea to generate too many p-values.
7. ### Comparing multiple dependant correlation coefficients

I did not understand your message fully but this seems to be a set-up for Repeated Measures Multivariate Analysis of Covariance (Repeated Measures MANCOVA). If the assumptions of plain vanilla Repeated Measures MANCOVA are not satisfied, you can run MANCOVA based on bootstrap.
8. ### Statistical Tests

You are using a time series model to estimate Wave Height. Therefore, you need to run time series diagnostics as part of the overall goodness-of-fit diagnostics. 1] Diagnostics based on residuals: define Residual = Wave Height - Predicted Wave Height. 1.1] Estimate autocorrelation function...

:)
10. ### Interpret Linear Discriminant Analysis and visualization

LDA requires that all the features be scale variables, not categorical or ordinal. Moreover, it requires that all of the features had joint normal distribution.... I know. Moreover, LDA requires that the covariance matrix of features in class A be the same as that in class B. That is what I...
11. ### Interpret Linear Discriminant Analysis and visualization

You do not have to scale. However, the variability of the features and their correlations must be the same in each class. If that assumption fails, LDA may misfire. There are other situations in which LDA misfires and is suboptimal to other classification methods... I'm afraid there are...
12. ### urgent help required - data analysis of time course

The p-value from the omnibus ANOVA test may be larger or smaller than the p-value for a t-test comparing just two particular groups. What matters is that there is only one ANOVA p-value but many t-tests (multiple testing). And none of those t-tests summarize the whole dynamics in a statistically...
13. ### Interpretation of second difference of a predictor

To some extent, the second difference is measuring whether the companies have generated more casfflows than last year or less.
14. ### urgent help required - data analysis of time course

Running multiple t-tests would no be right here... This is a set-up for repeated measures ANOVA with two factors: 1) Time: within-subjects factor, 2) Virus Type: between-subjects factor. You should start with the full factorial model (including the interaction of Time and Virus Type) and drop...
15. ### Interpretation of second difference of a predictor

Yous said earlier: " using S&P 2nd difference". How is that "the change in absolute changes"? You would need to state clearly what's going on.
16. ### urgent help required - data analysis of time course

Need to see the research questions, description of the data + experiment, attempted statistical methods, summary of the results. Just like I mentioned in my previous post... On the other hand, you keep repeating: "I did this little thing. Here's the output.."
17. ### Interpretation of second difference of a predictor

The return on the S&P portfolio is indicative of good or bad things happening to GDP, through market sentiment and such.
18. ### urgent help required - data analysis of time course

Typically, visitors to this side come with specific questions. They do not say: "Do the whole analysis for me. Please, please." You would need to state what you have done already, what the obstacles were and which research / programming / other questions you have now... Somebody nice here...
19. ### Need to find data | Repeated-measures/split-plot ANOVA

Can't you just cook up the data set if you do not care where the data come from? What is the ultimate purpose of the data set? Is it having something to test your code on, or is it something more serious?
20. ### Logistic Regression vs survival analyses in large cohort studies

Survival analysis will address all these questions if you study it carefully. This includes participants falling into different categories and some of them allowing intervention with a delay. It is not good to bin the data into cohorts. By applying such a crude discretization you are ignoring a...