0
votes
1answer
46 views

Eliminated items in Factor Analysis

I'd like to get your opinions on how to interpret items that had to be eliminated in factor analysis (FA). I've been researching consumer shopping motivations and ran a survey with 40 items, which ...
11
votes
2answers
277 views

What criteria must be met in order to conclude a 'ceiling effect' is occurring?

According to The SAGE Encyclopedia of Social Science Research Methods… [a] ceiling effect occurs when a measure possesses a distinct upper limit for potential responses and a large concentration ...
4
votes
4answers
347 views

If a measure is valid (but not necesarily reliable), can it be consistently replicated?

I had this question on an exam, and I was positive that the answer was A. The Beck Depression Inventory is a scale intended to measure depression levels, with higher scores indicative of higher ...
3
votes
1answer
97 views

Validation of a questionnaire in a new population

I have 400 responses to a 20 item questionnaire which purports to measure an attitudinal constuct in medical students. The instrument was validated in the US for a single year of medical students and ...
0
votes
1answer
121 views

Calculating total score for a scale including polytomous and dichotomous items [duplicate]

I have a variable that is measured using a 13-item, 4-point Likert scale with the exception of one item (yes $=1$, no $=2)$. How can I calculate the total score for this variable?
4
votes
3answers
169 views

How to check psychometric type of scales?

It is well known, that there are diffrent types of scales (see Wikipedia Level of measurement). In psycholinguistics there is Semantic Differential technique. It uses a scale (usually 5 or 7 grades) ...
3
votes
1answer
329 views

What is the correct use of Cronbach's alpha?

I am trying to use Cronbach's alpha in order to see if some variables are measuring the "same", but I have some doubts about the correct use: Can I compute alpha for numerical, ordinal or ...
1
vote
0answers
113 views

Confirmatory factor analysis for a newly constructed questionnaire

I am about to develop a new questionnaire with 142 questions I have performed exploratory factor analysis and 30 latent factors were extracted. I was wondering if it is necessary to perform ...
3
votes
0answers
103 views

Should I run measurement invariance if confirmatory factor analysis is not affirmative?

I have a repeated measures design for a Likert scale with 10 items. This scale is assumed to be unidimensional and this is one of the research questions along with the scales measurement invariance ...
3
votes
1answer
160 views

Summing up ordered items to a sum-score: implications?

It is common practice in psychology to add together ordered items to sum-scores, and then use these sum-scores for subsequent statistics. This is usually done without explicitly mentioning measurement ...
4
votes
1answer
3k views

4 point and 5 point Likert scales in a new questionnaire

I'm looking to confirm whether having a 4 point Likert Scale for some constructs, and a 5 point Likert scale for other constructs will be suitable when developing a questionnaire? I have 7 constructs ...
2
votes
2answers
2k views

Likert scale and yes/no calculation of one score

My survey is based on observations and interviews. The observation questions are yes/no type questions and interview questions are 4 points. $1=$ never, $2=$ sometimes, $3=$ usually, and $4=$ ...
2
votes
2answers
2k views

Omega vs. alpha reliability

I wonder if someone can explain what is the main difference between omega and alpha reliabilities? I understand an omega reliability is based on hierarchical factor model as shown in the following ...
3
votes
1answer
894 views

Designing and validating a Likert-type scale with odd or even response categories

As part of an advisory team in my educational institution for undergraduate nurses, I (among others) have been assigned to design a questionnaire that will assess students' and academic staff's ...
7
votes
4answers
2k views

Is 0 a valid value in a Likert scale?

I have carried out my pilot study on language learning motivation using a 6 point Likert scale but from 0 (strongly disagree) to 5 (very much agree). I noticed a colleague in his survey used 1 to 6. ...
2
votes
1answer
82 views

What is correct terminology when describing the number of response levels of a Likert scale?

I know that the Likert scale is the sum (or some sort of combination) of all the responses of a survey, test etc. and the actual numeric responses are called response levels. Is this true of all ...
10
votes
2answers
7k views

How to transform ordinal data from questionnaire into proper interval data?

Are there any straightforward methods of transforming ordinal level data into interval level (just as there are for doing it the other way round)? And performable in Excel or SPSS? Having the data, ...
2
votes
0answers
284 views

Maximizing Cronbach alpha to select the number of variables that define a given construct

I can't seem to find this anywhere on the internet or in my books. I'm putting together a construct for an underlying variable. Is it acceptable to have a construct with two variables if that ...
1
vote
3answers
1k views

What is the most effective way to combine different rating scales for the same data?

I have a collection of data which is inherently the same (would expect it to follow the same distribution) where some of it is rated with one scale of ordinal ratings and the rest of the data is rated ...
6
votes
2answers
915 views

Advice on scientifically sound scale construction

I've been given a set of 20 Likert-items (ranging from 1-5, sample size n = 299) within the field of organizational research. The items are intended to measure a latent concept which is ...
2
votes
1answer
373 views

Standard formula for quick calculation of scores

I have three datasets as follows: Dataset A can have a maximum score of 30. (Individual scores can be from 1 to 30) Dataset B can have a maximum score of 45. (Individual scores can be from 1 to 45) ...
4
votes
1answer
1k views

Which package to use for convergent and discriminant validity in R?

I am new to R and want to assess validity of some scales using R. Is there a package that I can use to test for convergent and discriminant validity in R?
1
vote
2answers
391 views

Rules of thumb for creating composite scales

Normally when I create an index I basically just take the or averages of the individual variables that comprise the index. But I'm wondering if one should / could not, take the product? E.g., a scale ...
11
votes
2answers
2k views

Assessing reliability of a questionnaire: dimensionality, problematic items, and whether to use alpha, lambda6 or some other index?

I am analyzing scores given by participants attending an experiment. I want to estimate the reliability of my questionnaire which is composed of 6 items aimed at estimating the attitude of the ...
7
votes
4answers
9k views

How to compute correlation between/within groups of variables?

I have a matrix of 1000 observations and 50 variables each measured on a 5-point scale. These variables are organized into groups, but there aren't an equal number of variables in each group. I'd ...
3
votes
0answers
2k views

How to carry out a Likert scale analysis?

Context: My research aims to assess whether parents who have been involved in a relationship with a social worker are at higher risk of child abuse/neglect. I am trying to establish whether there ...
2
votes
1answer
2k views

Internal reliability for an ordinal scale

My teacher is asking whether it is possible to look at the Cronbachs's alpha when looking at the internal reliability of an ordinal scale. She thinks, because you use the mean of it, it is not ...
8
votes
4answers
1k views

Can one validly reduce the numbers of items in a published Likert-scale?

[edits made in response to feedback- thanks :-) ] Doh! More edits! Sorry! Hello- I am doing some rather rough and ready data collection with a survey sent out to healthcare staff using a published ...
10
votes
3answers
3k views

Validating questionnaires

I am designing a questionnaire for my dissertation. I am in the process of validating the questionnaire I have applied a Cronbach's alpha test to the initial sample group. The responses to the ...
6
votes
2answers
1k views

Item Analysis for an R newbie

I am trying to assess a 20-item multliple choice test. I want to perform an item analysis such as can be found in this example. So for each question I want the P-value and the correlation with the ...
11
votes
3answers
4k views

Factor analysis of questionnaires composed of Likert items

I used to analyse items from a psychometric point of view. But now I am trying to analyse other types of questions on motivation and other topics. These questions are all on Likert scales. My initial ...