Standardized scores correlation positive instead of negative

I had to standardize the scores of a variable because the items composing it were measured on different Likert-type scales (5, 6, 7 points). After this, I ran a correlation between this variable and other variables, with which theoretically it is supposed to correlate negatively. This yielded though a positive correlation. Correct me if I'm wrong, but is this result due to the score standardization? Thank you!

• When you say you 'standardized the scores of a variable' do you mean you standardized the components before adding them, or you standardized the result after adding them? Commented Jan 5, 2014 at 23:06
• The scores were standardized before adding them. Commented Jan 5, 2014 at 23:18

No, it can't be due to score standardization, unless the standardization somehow involved multiplying by a negative number. I can't see why standardization would involve that, but you never know!

More usually, the standardization would be something like:

$S = 7/5*A + 6/5*B + C$

as opposed to

$S = A + B + C$

these two S will correlate very highly with each other and in the same direction with some other variable.

• Indeed, it could not have been standardization, thank you! Actually, I just realized it's a coding problem.. which is an entirely different problem. Commented Jan 5, 2014 at 23:20