Validity in Social Research

Validity refers to the extent to which an indicator (or set of indicators) really measure the concept under investigation. This post outlines five ways in which sociologists and psychologists might determine how valid their indicators are: face validity, concurrent validity, convergent validity, construct validity, and predictive validity. 

Validity refers to the extent to which an indicator (or set of indicators) really measure the concept under investigation. This post outlines five ways in which sociologists and psychologists might determine how valid their indicators are: face validity, concurrent validity, convergent validity, construct validity, and predictive validity.

As with many things in sociology, it makes sense to start with an example to illustrate the general meaning of the concept of validity:

When universities question whether or not BTECs really provide a measure of academic intelligence, they are questioning the validity of BTECs to accurately measure the concept of ‘academic intelligence’.

When academics question the validity of BTECs in this way, they might be suspicious that that BTECs are actually measuring something other than a student’s academic intelligence; rather BTECs might instead actually be measuring a student’s ability to cut and paste and modify just enough to avoid being caught out by plagiarism software.

If this is the case, then we can say that BTECs are not a valid measurement of a student’s academic intelligence.

How can sociologists assess the validity of measures and indicators?

what is validity.png

There are number of ways testing measurement validity in social research:

  • Face validity – on the face of it, does the measure fit the concept? Face validity is simply achieved by asking others with experience in the field whether they think the measure seems to be measuring the concept. This is essentially an intuitive process.
  • Concurrent validity – to establish the concurrent validity of a measure, the researchers simply compare the results of one measure to another which is known to be valid (known as a ‘criterion measure). For example with gamblers, betting accounts give us a valid indication of how much they actually win or lose, but wording of questions designed to measure ‘how much they win or lose in a given period’ can yield vastly different results. Some questions provide results which are closer to the hard-financial statistics, and these can be said to have the highest degree of concurrent validity.
  • Predictive validity – here a researcher uses a future criterion measure to assess the validity of existing measures. For example we might assess the validity of BTECs as measurement of academic intelligence by looking at how well BTEC students do at university compared to A-level students with equivalent grades.
  • Construct validity – here the researcher is encouraged to deduce hypotheses from a theory that is relevant to the concept. However, there are problems with this approach as the theory and the process of deduction might be misguided!
  • Convergent validity – here the researcher compares her measures to measures of the same concept developed through other methods. Probably the most obvious example of this is the British Crime Survey as a test of the ‘validity’ of Police Crime Statistics’. The BCS shows us that different crimes, as measured by PCR have different levels of construct validity – Vehicle Theft is relatively high, vandalism is relatively low, for example.

Source 

Bryman (2016) Social Research Methods

 

 

Playing the SENCO Game…

According to the latest Department for Education data, the number of pupils receiving extra time in exams in England and Wales has increased by 35.8% since 2013/14.

However, at the same time there has been a 20.4% decrease in pupils identified as having Special Education Needs.

This represents a real terms 4 year increase of 51.2% of pupils receiving extra time, relative to those pupils identified as SEN (which should give us an indication of the underlying ‘pool’ of pupils who are potentially eligible for extra time.

Here’s the statistics (full sources below)

SEN pupils

So what’s going on here? How do we explain this?

This Telegraph article points to the fact that a disproportionate amount of the increase in pupils receiving extra time is driven by kids (or rather parents) in Independent schools…they are twice as likely to receive extra time as kids in state funded schools.

This alone has to push you towards a combination of cultural capital theory and labelling theory in explaining what’s going on here – it’s extremely unlikely that kids in Independent schools have objectively (i.e. really) suddenly become more in need of extra time, relative to kids in state schools – and as the article alludes to, it’s probably down to middle class parents getting their kids assessed for extra time (and maybe those kids gaming the system?)

NB – the number of kids in state schools receiving extra time in exams has also increased, but not as fast as those in independent schools. (Might be interesting to subject this to regional analysis to see if it’s linked to income?)

VERY INTERESTINGLY, if you dig into the Access Arrangements data below, this aspect of the data doesn’t exist from the DFES (I assume it did once, otherwise said article wouldn’t have been written)

As to the increasing number of kids receiving extra time AT THE SAME TIME AS A DECREASE IN KIDS WITH SEN – this might reflect a polarisation – i.e. objectively there are fewer kids with ‘more serious’ SEN that require such exam concessions, but overall there are fewer kids with any SEN…

HOWEVER, once you dig even deeper into the stats below, what do you find…

Statemented kids are on the increase within state funded schools (where you get Pupil Premium for taking on statemented kids), while non statemented SEN kids are on the decrease (which you don’t get funding for, but you have to spend school resources on to keep OFSTED happy)

Compared to Independent schools – Statemented kids are on the decrease, while non-statemented kids are on the increase – and how do we explain the difference – these schools don’t get extra money for taking on statemented SEN kids like state schools, while they can get their kids extra time by doing their own ‘in-house’ SEN assessment.

NB – this is only one possible interpretation, and I’m prepared to stand corrected if anyone wants to pull me up on my less than perfect understanding of SEN funding and access arrangement policy!

Sources of Data

SEN data

https://www.gov.uk/government/statistics/special-educational-needs-in-england-january-2017

Access Arrangements

https://www.gov.uk/government/statistics/access-arrangements-for-gcse-and-a-level-2016-to-2017-academic-year

Telegraph Article

http://www.telegraph.co.uk/education/2017/11/30/one-six-children-now-given-extra-time-public-exams-official/

What is Reliability?

Reliability is the consistency of a measure of a concept. There are three factors researchers generally use to assess reliability: stability, internal reliability and inter-rater reliability

Reliability refers to the consistency of a measure of a concept. There are three factors researchers generally use to assess whether a measure is reliable:

  • Stability (aka test-retest reliability) – is the measure stable over time, or do the results fluctuate?  If we administer a measure to a group and then re-administer it and there is little variation in the results changed over time, the measure can be staid to have ‘test-retest reliability.
  • Internal reliability – are the indicators which make up the scale or index of a measurement consistent ?If the score a respondents according to one indicator of a measure are consistently related to the scores they achieve according to other indicators for that same measure, then the measure can be said to have ‘internal reliability’.
  • Inter-rater reliability – how much agreement is there over which observed empirical phenomena fit into what indicator? If researchers have a high level of agreement over how observed behaviour ‘map onto’ the indicators of a measure, then we can say the measure has a high level of inter-rater reliability.

Three ways to assess reliability

Source

Bryman, Alan (2016) Social Research Methods

 

‘Station’ based lessons for A level sociology

Last Updated on January 1, 2018 by Karl Thompson

Station based lessons are those in which the teacher sets up a number of different (and differentiated) tasks on different tables in the class room and students spend a set time at each table, moving from task to task.

I find these are most useful at the very beginning of the Winter and Easter terms, after students have done sufficient sociology to enable them to work through said tasks largely on their own, with the teacher acting only as a facilitator…

This is precisely what I’ll be doing with my Upper sixth groups when I face the horror and terror of going back to school on Thursday…. Station lessons make things a little easier…

Here’s one to try out, based on recapping consensus theories of crime and deviance, links to the resources are below.

Overview plan:

  • students spend about 30-40 minutes working through the 5 stations, 5-7 minutes on each of five separate stations.
  • students spend about 20-30 minutes ‘writing up’ the answers in the attached booklets.

Resources 

  • Consensus Theories of Crime Recap Lessons.
  • White board for task
  • A3 photocopies of pages 2-4 above for stations 2, 3, and 5.
  • Card sorts for task 4 (I don’t have these to hand, but you simply need cards with concepts, and pictures and perspectives – this is more of a general recap rather than a consensus theory of crime recap),

Station 1: White Board Station (AO1 – Knowledge)

  •  Explain your one of the consensus theories of crime in picture form – you may use three words also.

Station 2: AO1 Concepts Station (A01 – Knowledge)

  • Research and write in the definitions for two-three of the concepts
  • If you finish, add in an example or piece of supporting evidence which illustrates the concept

Station 3: Data Response Station (AO2 – Application)

  • Read the item, then for one theory write in how that theory would explain the case study in the item. 

Station 4: Card Game Station (AO3 – Analysis)

  • Game 1: Shuffle the concepts and theories cards – pick two (or three!) at random, suggest a link between them.
  • Game 2: Rank the ‘case studies cards’ – rank them in order of how well they support your assigned theory. 

Station 5: Evaluation Station (AO3 – Evaluation)

  • Add in as many evaluation points as possible for one theory
  • If you finish, then add in counter-evaluation to the previous evaluations of theories

Further comments

There’s not a lot else to say really… this was just a New Year’s post for all the sociology teachers out there, happy new year!