In the very broad field of psychology, Quantitative Methods is the indie college radio station of the group. The one who played U2 and R.E.M. in the 80s before ‘Sunday Bloody Sunday’ and ‘Man on the Moon’ became ubiquitous. The one who “discovered” the Red Hot Chili Peppers in the early 90s before Blood Sugar Sex Magic and the Grammys. Or who, more recently, broke the Black Eyed Peas before the addition of Fergie and all that commercial success.
Quantitative Methods is the kid with the nose piercing and the plaid shirt who was into Structural Equation Modeling, Bayesian Statistics, or Hierarchical Linear Modeling, before it was cool. The one who spent months in their room, poring over the catalogue, learning every facet of this statistical method, before letting go and sending it out into the world to be used by psychological researchers. Most of these methods were studied in depth by a very small group of Quantitative Methods Psychologists at one time but are now used widely throughout the discipline.
They’re also, in another way, the Rick Rubin of psychology. You know how the Red Hot Chili Peppers made the big time with Blood Sugar Sex Magic? Producer Rick Rubin. Slayer’s magnum opus Reign in Blood, Adele’s 21, the Beastie Boys breakthrough Licensed to Ill? Rick Rubin. And for psychological researchers doing in-depth work – whether that be on depression, or vaccine confidence, or PTSD in military couples – the producer working behind the scenes to ensure scientific rigour is Quantitative Methods. The Quantitative Methods Psychologists help them craft their study to determine the best way to collect that data, to account for unforeseen wrinkles, and the sample size that is required to detect relevant effects.
Dr. Rob Cribbie is the Chair of the Quantitative Methods Section at the CPA, and a Quantitative Methods Psychologist in the Department of Psychology at York University. He says,
“It’s about research methods and the analysis of data. People who work in Quantitative Methods do everything from consulting on sample sizes, research designs, and the analysis of the data to researching new or improved methods for analyzing data. We also go into the psychometrics of the tools we use and how well they work.”
So what does this kind of work look like, on a day-to-day basis? What exactly does a Quantitative Methods Psychologist do? Dr. Milica Miočević is the Secretary/Treasurer of the Quantitative Methods Section, and a Quantitative Psychologist in the Department of Psychology at McGill. She gives an example:
“I recently published a paper with a co-author from biostatistics on power prior distributions. We were trying to find a way to use historical data from a study that’s related to the current study, but conducted using a sample from a slightly different population. We thought of ways we could quantify the differences between the participants in the previous study and participants in the current study, and tested whether using our method with data from a previous study can improve inferences in the current study. The article that we published will allow researchers in psychology to rely on historical data to improve statistical inferences of new research studies without requiring prohibitively large sample sizes.”
The field itself is, in a way, rather new. The Quantitative Methods Section of the CPA is celebrating its tenth anniversary this year, and the discipline, while widely recognized today, was much less familiar ten or twenty years ago. Says Dr. Cribbie,
“I remember when I was interviewing for jobs, around 2000, most of the interviewees were asking ‘what’s your area of psychology?’ And I would answer ‘quantitative methods’, and they would say ‘no, we mean – is it depression, is it clinical, cultural – what do you study?’ And I would say ‘well…quantitative methods’. They didn’t see this as a discipline. There’s been quite a shift. Now it’s totally mainstream to say ‘I’m a quantitative psychologist’. The area of Quantitative Methods is so broad now, and there are so many tools that we use, that you really need people who specialize in the different methods.”
With the growth of the field has come a sea of change in the ways psychologists analyze and interpret data. The advent of software programs like R and others have opened up a world of possibilities that were a lot more difficult, even inaccessible, 20-25 years ago. And it is constantly changing. As a new method becomes popular and widespread throughout the world of psychology, quantitative methods psychologists have already moved on to something else entirely. Dr. Miočević says,
“We go through waves of what’s interesting and what we think needs to be developed more. When I was in grad school, Bayesian methods were becoming the popular topic. Now, it seems like it’s Machine Learning, and we’ll see what the next thing is. I feel like every few years we add something new to the quantitative methods toolbox in psychology. Sometimes the novel approaches are coming from statistics, sometimes they are coming from other fields like economics. There has been a lot of change in my ten years!”
You know that one pop song you really like? The one by Taylor Swift or Dido or Alicia Keys or Imagine Dragons with the guest rapper? That guest rapper is Kendrick Lamar. Quantitative Methods is, in a way, the Kendrick Lamar of psychology, though they will likely never get the solo recognition that he did when he won the Pulitzer Prize. They will collaborate with anyone from any discipline, any time – so much so that after a while you barely notice they’re there. Every facet of psychology, every individual discipline, is informed by the latest tools for data analysis, the most up-to-date research methods and practices, and the scientific rigour provided by Quantitative Methods. Says Dr. Cribbie,
“Quantitative Methods span all the areas of discipline. So, if you were to take every section of the CPA, Quantitative Methods play a role in every one of those sections. It’s great that there is this section that allows people with this interest to discuss new and different methods, and ways in which people apply these tools.”
It is for this reason that Psychology Month 2022 kicks off with Quantitative Methods – it is the one section that informs all other sections. Dr. Cribbie, Dr. Miočević, and their colleagues are the cool kids on the block who were way into that research method long before you’d even heard of it. You can follow the Quantitative Methods section on Twitter - @cpa_qm – on their website https://canadianquantpsych.wordpress.com/ or through their section newsletter https://cpa.ca/sections/quantitativemethods/newsletter/ so you, too, can be one of the cool kids who knows things before anyone else!