The Knot's Real Wedding Study 2017

The Knot, a wedding planning website, collected data on the amount of money that brides and grooms spend on items for their weddings. They shared this information, as well as the average cost of a wedding in 2017. See the infographic below:

BUT WAIT! If you dig into this data and the methodology, you'll find out that they only collected price points from couples who ACTUALLY PAID FOR THOSE ITEMS.

https://xogroupinc.com/press-releases/the-knot-2017-real-weddings-study-wedding-spend/

Problems with this data to discuss with your students:
1) No one who got stuff for free/traded for stuff would have their $0 counted towards the average. For example, one of my cousins is a tattoo artist and he traded tattoos for use of a drone for photos of their outdoor wedding.
2) AND...if you didn't USE a service, your $0 wasn't added to their ol' mean value. For example, we had our wedding and reception at the same location, so we spent $0 on a ceremony site.
3) As pointed out by Stephen Chew on Twitter, there is no measure of variability.

What does this mean? A wedding planning website that makes money by advertising things for weddings inflated the costs of weddings.

How to use in class:
a) A great example of bending the truth with actual data points.
b) An example of averages.
c) Why didn't they use median values?
c) If you are a social psychologist teaching stats, this example illustrates how data can be used to create a social norm ($33K wedding) and that norm can be used to exert pressure on people to spend more money at their wedding.

Ways to use funny meme scales in your stats classes

Have you ever heard of the theory that there are multiple people worldwide thinking about the same novel thing at the same time? It is the multiple discovery hypothesis of invention . Like, multiple great minds around the world were working on calculus at the same time. Well, I think a bunch of super-duper psychology professors were all thinking about scale memes and pedagogy at the same time. Clearly, this is just as impressive as calculus. Who were some of these great minds? 1) Dr. Molly Metz maintains a curated list of hilarious "How you doing?" scales. 2) Dr. Esther Lindenström posted about using these scales as student check-ins. 3) I was working on a blog post about using such scales to teach the basics of variables. So, I decided to create a post about three ways to use these scales in your stats classes: 1) Teaching the basics of variables. 2) Nominal vs. ordinal scales. 3) Daily check-in with your students. 1. Teach your students the basics...

Leo DiCaprio Romantic Age Gap Data: UPDATE

Does anyone else teach correlation and regression together at the end of the semester? Here is a treat for you: Updated data on Leonardo DiCaprio, his age, and his romantic partner's age when they started dating. A few years ago, there was a dust-up when a clever Redditor r/TrustLittleBrother realized that DiCaprio had never dated anyone over 25. I blogged about this when it happened. But the old data was from 2022. Inspired by this sleuthing, I created a wee data set, including up-to-date information on his current relationship with Vittoria Ceretti, so your students can suss out the patterns that exist in this data.

Tyler Vigen's Spurious Correlations

Tyler Vigen has has created a long list of easy-to-paste-into-a-powerpoint graphs that illustrate that correlation does not equal causation. For instance, while per capita consumption of cheese and number of people who die by become tangled in their bed sheets may have a strong relationship (r = 0.947091), no one is saying that cheese consumption leads to bed sheet-related death. Although, you could pose The Third Variable question to your students for some of these relationships). Property of Tyler Vigens, http://i.imgur.com/OfQYQW8.png Vigen has also provided a menu of frequently used variables (deaths by tripping, sunlight by state) to help you look for specific examples. This portion is interactive, as you and your students can generate your own graphs. Below, I generated a graph of marriage rates in Pennsylvania and consumption of high fructose corn syrup. Generated at http://www.tylervigen.com/

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