Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [checking]

very ambiguous, try to find a more descriptive tag, like *diagnostic* or *residuals* or *model-evaluation* ...

21 questions
94
votes
6 answers

Essential data checking tests

In my job role I often work with other people's datasets, non-experts bring me clinical data and I help them to summarise it and perform statistical tests. The problem I am having is that the datasets I am brought are almost always riddled with…
Chris Beeley
  • 5,465
  • 5
  • 36
  • 40
7
votes
1 answer

Most efficient way to check answers to exercises when learning from a statistics textbook?

There's a community wiki at: Free statistical textbooks that has a nice list of freely available textbooks on statistics. Many of the textbooks that people suggest have exercises at the end of each chapter which is great, but very few of these…
9fpqhijf7zm1qrgn760r2hzipi92n7
  • 11
  • 1
  • 3
6
votes
1 answer

What is posterior predictive check, and how I can do that in R?

I am using Bayesian hierarchical modeling to predict an ordered categorical variable from a metric variable. For example, I want to regress Happiness (in 1-5 ratings) on Money (a metric variable): Happiness∼log(Dollars) After estimating posterior…
Ho1
  • 327
  • 5
  • 14
5
votes
3 answers

Foundations behind Linear Regression / Statistical Modelling

I've always struggled with the foundations behind the concept of modelling (and specifically regression) - what is random, what is not, what we are modelling. I think I have a grasp of it - but I'd love if someone could please confirm if this…
user523384
  • 569
  • 2
  • 7
5
votes
1 answer

What is a good academic citation for cross-validation?

I performed a holdout cross-validation analysis on a multilevel model fit. The purpose of this was to show that we didn't have a problem with over-fitting, for which it worked just fine. Now we are writing it up for publication and I need a citation…
yolio
  • 51
  • 2
5
votes
1 answer

numerical measure for an ordered list

At the end of every semester I have to input my students' grades into a database. Typically this means I go one by one down my list of grades from my excel spreadsheet and manually fill the grade into the db application. One way to check I have done…
Geoff
  • 451
  • 2
  • 14
4
votes
2 answers

How to find duplicate cases in a large dataset?

I have a large dataset which is made up of responses from 600 shoppers on 15 variables. When I tally the responses, it comes to 603. I know there were 600 respondents, so I must have recorded the responses of three people twice. Instead of checking…
Adhesh Josh
  • 2,935
  • 16
  • 50
  • 67
3
votes
3 answers

How to check a similar question in a survey

I have a survey in which I asked, "Would you be ready for a t-shirt shop in St Jean Avenue? [yes/no/don't know]". Then I asked many other questions, ultimately including, "Would you be ready for a t-shirt shop in St Jean Avenue knowing that the…
S12000
  • 528
  • 1
  • 4
  • 14
3
votes
1 answer

Concerns about data for regression model

I'm building a model that predicts goals scored based on the defenses that a player faces. From the classes I've taken, you should normalize the response variable. Here is the issue I'm facing: the value for Goals will usually be 0,1,2,3 or 4…
madsthaks
  • 277
  • 3
  • 11
3
votes
2 answers

How to calculate derivative of the contractive auto-encoder regularization term?

Setup I found a paper on that has a varient on normal auto-encoders (contractive) which for its gradient uses the following regularization penalty: $$\left|\left|J_f(x)\right|\right|^2_F = \sum_{ij}{\left( \frac{\partial h_j(x)}{\partial x_i}…
Ranon
  • 328
  • 1
  • 5
3
votes
1 answer

Is the linear probability model generalisable to ordered logit/probit regressions?

I have a set of data where the dependent variable is an ordered response with 7 levels and I've fitted an ordered logit model to the data, and now I want to conduct some robustness checks on the estimates. Is the Linear Probability Model for binary…
Spcogg
  • 33
  • 5
2
votes
1 answer

Checking model, the same variance, in one-way ANOVA test

\begin{array} {|r|r|}\hline A & B & C \\ \hline 24 & 21 & 16 \\ \hline 18 & 26 & 22 \\ \hline 27 & 32 & 19 \\ \hline 28 & 25 & 17 \\ \hline \end{array} At the significance level of $\alpha = 5\%$, compare the average number of tomatoes produced…
Cường Đặng Cao
  • 31
  • 2
2
votes
1 answer

Naive bayes computation of denominator

I'm wondering about the denominator in this computation : P(Banana|Long, Sweet and Yellow) P(Long|Banana) * P(Sweet|Banana) * P(Yellow|Banana) * P(banana) = _______________________________________________________________ …
baxx
  • 738
  • 6
  • 21
2
votes
0 answers

Model checking versus posterior predictive checks

I am interested in knowing if there are any difference in modeling checking versus posterior predictive checks in the Bayesian framework. Are posterior predictive checks a type of model checking?
stochasticcrap
  • 213
  • 1
  • 2
  • 5
1
vote
1 answer

Does a strong checksum provide reasonable assurance of absolute data integrity?

Does a checksum ensure absolute data integrity? That is, if a piece of data several gigabytes long changes a single bit, the odds are dependable that the checksum will be different, particularly with strong hash functions like SHA256? Phrased…
JamesTheAwesomeDude
  • 185
  • 4
1
2