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24 views

Methane Flux Undergraduate dissertation [closed]

I'm trying to do a research project into how methane (units mg CH$_4$ m$^{-2}$ d$^{-1}$) and CO$_2$ flux (units mg CO$_2$ m$^{-2}$ d$^{-1}$) in a Canadian peatland is influenced by temperature, soil ...
3
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1answer
49 views

Research methodology, statistical literacy and communication

When talking to clients or offering advice, I often find myself having to question the choice of plotting variables over time. For example, if a client is interested in understanding the relationship ...
1
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0answers
10 views

Multiple groups - how to regularise estimate of level 1 parameters based on level 2

I am fitting some relatively complex structural equation models, but the specific model is not so important. I am estimating multigroup models, such that one parameter is completely free across ...
2
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0answers
30 views

Violating Independence - Methodological Question

I am looking again at a popular statistical testing method used in finance, suspect it's a bit naughty, but would like to have a more experienced eye take a look also. The method is the following, ...
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0answers
5 views

making for making dataset for spam classifier

I'm trying to make a dataset for spam detection, what is the best automatic selection that I can use for picking up the word that should i count for my spam base ? Thank you
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0answers
39 views

Methodological advice

I need some help validating the statistical methodology I'm trying to use to analyze some data. My data is from a repeated measures study where each participant did two activities. Half of the ...
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4answers
207 views

A summary of econometric methods

Scikit Learn has a guide for machine learning techniques. Matthias Vallentin did a remarkable cheat sheet/cookbook for probability and statistics. Many heavy summaries of econometric methods are ...
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0answers
15 views

post-stratification of ACS survey

I have a survey methodology question. I am preparing a report that contains some demographic information. My supervisor instructed that I use the NCHS bridged-race population estimates when reporting ...
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0answers
10 views

methodology for assessing experimental design

I have pre post data for 5 different groups of kids living in different settings (rural, low income, high income, etc). The variables include age, gender, type of setting, treatment (exposure to one ...
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2answers
30 views

Is there any good reference which statistical test should be used given study design?

I am looking for a source (infographics, picture, graph, list, book, algorithm or whatever) that clarifies which statistical test should be used when. I mean what do I use when I have two unpaired ...
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0answers
30 views

What statistical test is fit for comparing enzyme activity profile of microbial strains

Enzyme activity profiles are profiles of (fungal, bacterial etc.) strains. Usually they are done by using predefined and standardised kits. One of those is for example ''api ZYM (BioMerieux)'' which ...
0
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0answers
26 views

Analysis to use with categorical predictors and continuous response variables

I am trying to figure out what the right statistical test to use is for data where the DV is continuous, and the IV's are categorical. There are a lot of different DV's that I want to run through a ...
2
votes
1answer
49 views

Is this method of finding the confidence interval correct?

Suppose that we have 2 sets of data $X = x_1, \dots, x_n$ and $Y = y_1, \dots, y_m$ and a test $T$ that tests the null hypothesis that these data come from a distribution with the same median. $T$ can ...
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0answers
11 views

types of baseline modelling

I'm searching for a model that can be used to decompose incremental effects and baseline effects and is also good at prediction (i.e. Not OLS). We have tried OLS, ARIMAX with exogenous factors, ARIMAX ...
4
votes
2answers
158 views

Unwritten laws and dirty tricks to influence the outcome of a regression analysis

Background: Some years ago, I was working for a professor specialized in macroeconometrics. As a student research assistant, it was my task to replicate other papers and "play around" with the data. I ...
2
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0answers
43 views

Help finding method of estimating regression parameters for a given performance

Pardon my ignorance, for I have very basic training in statistics, but have never taken a regression course. I ran an experiment where participants are in one of two conditions (between subjects). ...
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0answers
24 views

How did Gallup form this index?

I am reading this Gallup poll, and in it there is a "Positive Experience Index" that is used without really explaining how it was created, and therefore what, precisely, it means. From reading the ...
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2answers
52 views

What is the correct term for testing a classification method on different subsets of the same data

I am searching for the correct definition of a methodology I am using to test the robustness of different classification methods. I am creating different subsets of the full dataset by cutting away ...
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0answers
14 views

How to analyze a variable measured on a Likert scale and its interaction with another variable? [duplicate]

I have to analyze this variable which consists of scores given to 3 items (1-9 scale). This "Likert scale" measures "brand commitment" if thats important. 1) Firstly, should I compute 1 new variable ...
0
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2answers
76 views

What is the reasonable methodology to study machine learning techniques efficiently?

Nowaday, there are lots of online courses related to machine learning, and there are lots of programming languages which can be used to do data mining, such as R, Python or Matlab. For example there ...
0
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1answer
25 views

Non-differentiation

I'm trying to assess the level of non-differentiation for a web survey I am doing. It features six pages of several Likert items on each page with a 6 point scale, followed by a seventh page of ...
2
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0answers
55 views

How to handle unequal sample size with multiple factors?

The following dataset shows observations (count data) of cedar trees growing in small, medium, or large forest gaps (i.e. openings). You can see that that there is an unequal sample size and ...
4
votes
1answer
316 views

Can Goldman Sachs' economists predict who will win the World Cup?

Goldman Sachs decided to apply their brains to predicting the winner of the World Soccer cup. They built a statistical model analyzing past winners. I read about it here, but the original version ...
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0answers
19 views

Divide and Conquer

Satellite-Routed sensor system has attracted attention in next generation network. In this system large number of sensor terminals send sensed data to the monitoring station located in different area ...
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0answers
12 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?
5
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1answer
246 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 ...
1
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1answer
28 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 ...
2
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0answers
33 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 ...
0
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0answers
43 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
votes
1answer
132 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
28 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
28 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, ...
0
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1answer
22 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 ...
13
votes
1answer
837 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 ...
0
votes
2answers
111 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
votes
1answer
208 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
364 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
56 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 ...
0
votes
1answer
60 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. ...
3
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0answers
59 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 ...
13
votes
1answer
899 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
votes
1answer
28 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 ...
4
votes
1answer
110 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 ...
0
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0answers
31 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 ...
2
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0answers
104 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) ...
1
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2answers
894 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 ...
1
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2answers
89 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, ...
3
votes
1answer
59 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
votes
1answer
123 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
votes
1answer
132 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 ...