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7 views

Methods for analyzing pre/post test data [duplicate]

What methods of analysis are utilized for pre/post test data when outcome are knowledge scores? In addition what methods of analysis would be used for Likert behavioral score data?
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1answer
197 views

What is the right attitude toward open source machine learning toolkits?

There are lots of machine learning toolkits nowadays, such as weka, sklearn, R libs. If we choose to use these toolkits, besides that it is convenient, sometimes ...
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1answer
22 views

Multiplicative error in survey data

I'm working on a panel survey data where each individual's income was multiplied by a individual-specific random number (each random number is evenly distributed from 0.5 to 1.5) to avoid any ...
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0answers
18 views

Hierarchical classification

I'm currently working on the classification with massive amount of data. Similar to the kaggle one. Data input consist of features and multiple labels that can be hierarchically aligned. At first I ...
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0answers
38 views

three variables chemical data analysis optimization

Could anybody help me by giving a solved step by step example of response surface methodology (RSM) using Doehler design for leaching of metals or for chemical processes? My supervisor has given me ...
0
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1answer
25 views

How to give the input of an image to SVM after preprocessing

I got a dataset of images(GRAZ_02 Data set-Cars,Bikes,People) and extracted features from each and every image in the database using a descriptor(SIFT algorithm) that returns a matrix of order :(No. ...
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0answers
27 views

What is the difference between “data mining” and “data analytics”? [duplicate]

What is the difference between "data mining" and "data analytics"? Are both things the same technically?
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0answers
21 views

Experiments for performance testing software

I am looking to run a series of performance tests for a software system across different configurations and determine which combination works best. The software system processes a number of files, ...
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1answer
19 views

sampling question

I have a question about inclusion criteria to obtain a representative sample of people with "sustained" or uncontrolled high BP. A colleague proposed that I look at health history data retrospectively ...
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1answer
426 views

Is a priori power analysis essentially useless?

I attended a meeting of the Society for Personality and Social Psychology last week where I saw a talk by Uri Simonsohn with the premise that using an a priori power analysis to determine sample size ...
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0answers
31 views

Convert Likert scale to pairwise?

I want to find a way to convert the Likert scale to Pairwise (AHP/ANP) scale, because my questionnaire contains 30 criteria to compare, and making a pairwise questionnaire will contain (30*(30-1))/2 ...
8
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1answer
149 views

Should I report credible intervals instead of confidence intervals?

After stumbling upon the concept in a statistics textbook, I tried to wrap my head about it, and finally came to a conclusion which seems to fit all the explanations which I have seen so far: A ...
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2answers
131 views

What is the name of the survey method for determining the rank order of multiple items using a multiple question process?

I have seen surveys that use the following method to rank multiple items against each other. Let's say you have 25 items and you want to know their rank order (according to the survey-taker's ...
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0answers
36 views

Aside from regression coefficients, what are commonly used approaches to measure one variable's “sensitivity” to another variable?

I am about to embark on a lengthy study for a work project. At the core of it is the need for a statistical tool to help quantify "sensitivity." I am the lead software developer on the task, but I ...
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1answer
51 views

how do i tranform my ols equation into logs?

Hi i'm reading threw all my statistics notes and i can't find any mention of how to transform ols variables into logs. ie i can't see a equation or any method of turning a beta value into a log form. ...
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0answers
56 views

Proper Sampling - can I collect a two-group sample this way without issues?

I need to collect a two group sample for a comparison analysis (perhaps using logistic regression). The population that I need to extract a sample from is all firms from country A with activities in ...
12
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1answer
375 views

How to visualize a 3-D density function?

What is the best way graphically to visualize a 3-D density function? As in I would like to visualize $$z=f_{X,Y}(x,y)$$? Not necessary but R code for this would ...
3
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1answer
25 views

Calculating linguistic diversity of a text with respect to size

I'm doing linguistics work and I'm trying to make a measure of linguistic diversity in a text. A simple calculation seems to be linguistic uniformity ( or diversity) = number of words / unique words ...
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1answer
64 views

Avoiding fallacies when analysing individual data at group level

Let us say that you are running an experiment comparing a number of conditions. You have a database of individual scores, nested in groups, which are then nested by condition. Are there any ...
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0answers
27 views

Compare differences or ratios of factors by time

I observe a process in which particles could be detected on a start point, and sometimes cross a border. So I count the number of particles during the days. Which non-parametric method would you ...
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0answers
8 views

Make decision which is the relevant value

How to make a decision which key has significant more value then the other for each week? I have no idea how to express this. I think I can only count the number of each key and could compare their ...
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0answers
75 views

Which confidence intervals should be used?

I would like to plot 95% confidence intervals for my data. It seems there are multiple options for calculating them, e.g.: (examples shown using R code) ...
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2answers
324 views

Shall I use weekly or monthly data for forecast?

I seem not to find this in any textbooks. So I post these questions. Is monthly data better than weekly data for forecasting? Can there be seasonality in weekly data? Most software/methods don't ...
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2answers
85 views

Method to find pattern

Assume I tracked the behavior of users when they visit a Website. In detail I track the movement from which site to site they click within the Website. So I have a lot of tuples with (userID, site, ...
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1answer
56 views

Measuring how close a given sample distribution is to an ideal distribution

I'm trying to fashion survey experiments for which the demographic composition of the samples needs to be as close as possible to a 'golden' composition. For concreteness, let's say the 'golden' ...
3
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1answer
77 views

Method to jointly estimate Logit and OLS models

I am working on the following two models. Logit: Binary outcome $y$ ($y=1$ if paid more than the item value to win the item, $y=0$ otherwise) $$ y=b_0+x_1b_1+x_2b_2+x_3b_3. $$ OLS: Continuous ...
0
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1answer
90 views

Which statistical test to use? Paired-sample or independent-sample?

I have 1 subject rating 40 participants on the big five personality traits and other variables. these 40 participants are in 2 conditions (20 each). I want to compare whether there is a difference ...
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0answers
72 views

How to run a sensitivity analysis with dependent variables?

I am trying to run a sensitivity analysis on an efficiency indicator: the ratio between nitrogen outputs (milk, meat, crops) and nitrogen inputs (fertilizers, cattle feed, symbiotic fixation…). I ...
3
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1answer
219 views

Implementations of clustering with asymmetrical distance/similarity matrix

In my clustering problem I'm working with custom similarity measure and looking for any implementation of algorithms with asymmetrical distance or similarity matrix. I'm only interested in those that ...
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1answer
36 views

Estimating the number of birds in a specific area

I want to count the birds in an area. What's the proper statistical method for it? What are the good references for this topic?
4
votes
1answer
121 views

Confidence intervals based on the CLT: ever useful?

Suppose, for concreteness, that I am trying to estimate the mean of a population using a random sample of size $N$. Many elementary books discuss forming a confidence interval for the population mean ...
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0answers
45 views

logdif modell different from log model

I'm not sure if a 1st difference transformation was a good idea. ADF of the dependent variable gave me 0.1177, so I couldn't reject unit root hypothesis, other unit root test though rejected the unit ...
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2answers
56 views

How to assess the improvement from a treatment?

When optimizing a computer program, I need to determine how much faster the program runs with the latest optimization. To do this, I run the program N times without the optimization and N times with ...
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0answers
67 views

Using ANOVA to analyse a distribution

I found a method in an paper, which I do not quite understand. In this experiment the influence of a within subject factor was analysed. In order to analyse the influence of the factor not only on ...
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0answers
26 views

Finding kind of dependency

I have an interesting (to me) real-life problem but only a very basic understanding of statistics. I would appreciate a pointer to literature as I understand actually solving the problem is my ...
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0answers
52 views

Glasserian Grounded Theory Building Blocks

On reading the FAQ I was in hope this question pertaining a particular aspect of grounded theory would fall under data analysis. I appreciate if you would point me to which other community I should ...
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1answer
237 views

Achieving statistical significance in an A/B test

Out of one pool, I've randomly selected a small group (group A) and put everyone else in group B. Then, I'm observing whether or not they take a desired action. If I'm looking to test at a 95% ...
4
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1answer
108 views

Research Methodology on Fareless Bus System

I am working on a project for a Masters Project. The town I am looking at Switched to a Fareless system in Feb 1, 2011. I want to look and see if this increased ridership by a substantial amount. I ...
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1answer
1k views

Which statistical method to use in survey-based quantitative research?

I hope you can help me because at the moment I am confused and helpless. I am final year PhD student, and my supervisors asked me to find out statistical methods other than exploratory (percentage of ...
3
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2answers
91 views

Measure to capture clustering in time based event

I am searching for a good measure to capture clustering in time based events. Say that for a given interval of 5 minutes, cars randomly pass in front of house ... say one car at every 10 seconds (for ...
3
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2answers
413 views

Effect of one independent variable of several dependent variables – best strategy?

I have a question regarding which analysis strategy is best suited for our objective. In an exploratory study based on data from a survey we conducted ourselves in India, we are analyzing the ...
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5answers
207 views

Is it ok to fit a Bayesian model first, then begin weakening priors?

When doing frequentist stats, there is a long list of big no-nos, like looking at the results of statistical tests before deciding to collect more data. I'm wondering generally if there are a similar ...
3
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1answer
194 views

The biggest difference between medical statistics and biological statistics

I am turning my work from medical statistics into biology statistics (fishery). I am wondering if there is a big differences in methodology or focus between these two fields? In medical field, we do a ...
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2answers
634 views

Statistical test to compare multiple treatments on the same 'individual' over time

I'm looking for a statistical test or tests to compare the effects of different 'treatments' on a single 'individual' over time. The single 'individual' could be one person or a group acting as a ...
3
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5answers
2k views

What is the simplest statistical analysis to compare 2 groups on a simple survey?

I designed a simple survey about cancer knowledge among adults. There will be two groups: Those that have first-hand experience with cancer (you or someone in your immediate family with cancer) and ...
6
votes
1answer
218 views

Is Ye Shiwen's 400m IM performance in Olympics “anomalous” statistically?

The 16-year-old Chinese swimmer Ye Shiwen swam more than 5 seconds faster than her personal best in women's 400m individual medley in London 2012 Olympics, winning her a gold. Her performance received ...
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2answers
556 views

Is Joel Spolsky's “Hunting of the Snark” post valid statistical content analysis?

If you've been reading the community bulletins lately, you've likely seen The Hunting of the Snark, a post on the official StackExchange blog by Joel Spolsky, the CEO of the StackExchange network. He ...
3
votes
1answer
4k views

Determining sample size necessary for bootstrap method / Proposed Method

I know this is a rather hot topic where no one really can give a simple answer for. Nevertheless I am wondering if the following approach couldn’t be useful. The bootstrap method is only useful if ...
2
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0answers
65 views

How to analyze factors that have missing by design values for certain observations?

I am using an analysis for an experiment that I consider suboptimal. I am asking for any suggestions to improve this. I will briefly outline the experiment and what I’ve done, then ask your advice. ...
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3answers
186 views

Resources or methods for determining if a technique is in current use?

I know that this question is hard to answer, but I was wondering how you would determine if a statistical technique was in current use, or if it had a heyday a couple of decades ago but it's either ...