to triangulate

18:32 Oct 5, 2017 

What you have just described is not triangulation as the term is used in surveying.

17:58 Oct 5, 2017 

from 2 beacons (or in relation to some reference points), but you need a third one for cross-checking and evaluating the precision of your calculations. So back to square one: 3 readings needed for any reliable cross-checking.

13:44 Oct 5, 2017 

It's not really correct to say that this involves three readings. It involves two, but the crucial point is that they are angles, not distances. Triangulation is a method of determining the position of a point C by reference to two other points of known position, A and B. In each case what is measured is the angle between the line from each observer to the point (AC and BC) and the baseline (AB). Once you have the two angles you can draw a triangle, ABC, where C is the apex, and its position can be precisely determined without measuring any distances.

10:00 Oct 5, 2017 

As shown by Gallagy below, this term has undergone a partial change of meaning after being borrowed from surveying by the social sciences. For statistical data, the use of the term in the social sciences is, however, closer to the original usage.

@Daryo: in surveying or mapping, each of the three readings is not just used "for confirmation of the other two", though if the three readings do not converge at a single point, that does indicate inaccuracy of at least one reading; however, at least two readings are necessary to plot position and taking three readings adds reliability or reveals (and indicates the scale of) error.

08:49 Oct 5, 2017 

No Misuse

the verb triangulate and noun triangulation are frequently used in research, particularly in the social sciences.
https://www.ncbi.nlm.nih.gov/pubmed/25158659 "Triangulation refers to the use of multiple methods or data sources in qualitative research to develop a comprehensive understanding of phenomena (Patton, 1999)."
or http://journals.sagepub.com/doi/pdf/10.1177/1558689812437100
There are various types of triangulation as well. And yes, it means cross-checking the data from 1 source against at least 2 others =at least 3. Note there can be a mix of qualitative and quantitative data or methods of collection and a slightly different definition here: http://www.qualres.org/HomeTria-3692.html
"Rather than seeing triangulation as a method for validation or verification, qualitative researchers generally use this technique to ensure that an account is rich, robust, comprehensive and well-developed..."

22:54 Oct 4, 2017 

validation of data through cross verification from two or more sources...

adding implied parts:

validation of data from one source through cross verification from two or more other sources...

that makes at least 3 sources: the one being verified + 2 other

That's the general idea - as for this ST it's possible that each participant had only one supervisor ...

20:29 Oct 4, 2017 

But there are only two sources: participants and supervisors. I agree with Jack, 'cross-checking' is the correct term to use in this context. It would be 'triangulation' if there were at least three sources.

20:16 Oct 4, 2017 

more "applied to another field by analogy"

the point of the triangulation in surveying is the cross-checking of results from 3 readings / 3 different sources, same as this "triangulation": each source is used for confirmation of the other two.

19:29 Oct 4, 2017 

Thank you very much!

11:38 Oct 4, 2017 

I think what they mean is "cross-check". "Triangulation" is a process in surveying in which bearings are taken on something from three positions, thus enabling its precise position to be determined. I don't think "triangulate" can be correctly used in this context.