I'm going to start from assumption that you know nothing and work up -- so don't be insulted if I start too simple

• frankly, math and statistics gives me a headache, so I don't see any reason to inflict it on you more than absolutely necessary
  
  
• wanna hear everything I know about statistics? (Pause) Want to hear it again?
  
  And I was a test development specialist for 10 years and I still don't know how to calculate 3/4 of the statistics I used -- that's what computers and your local statistician are for
  
  
• so what is important in this course is not so much calculating the numbers as understanding the concepts

How many of you have math anxiety? -- intimidated by math?

People (administrators, test salespersons) know that 85% of classroom teachers are intimidated by math and are counting on it to get their own way -- They will purposely try to use stats to intimidate you

• 90% of it is a smokescreen
  
  
• these people do not necessarily know ANYTHING that you don't
  
  
• they just have a type of jargon they can use to impress the gullible
  
  
  UNLESS you give up, say "Oh well, its math, they must be right"

LOOK AT THIS MASS OF NUMBERS:

• completely incomprehensible, right?
  
  
• government official, salesman shows you this and says that it demonstrates that this is a great test item, you just have to take his word for it, right?
  
  Rubbish!
  
  
• this is what faced me the first day of my job with the Evaluation branch, and I figured it out eventually --> made my living doing this for a decade
  
  
• Now, is there anybody left in this room who still believes that I'm smarter than they are?
  
  
  • NO WAY --> if I can do this, you can do this
  
  
  
• so, don't panic for next couple of classes
  
  

• salesmen and administrators will try to cram standardized tests down your throat--> and if you don't learn this stuff you won't be able to resist
  
  
• you learn it, you can start asking intelligent questions (for which they mostly do NOT have answers) and then you can say, "Well, yes, but in my professional judgement, I think that would be a mistake" and they have to go away and leave you alone
  
  Choice between being a professional, and being a victim

  of "Math Anxiety personified".

Okay, let's generate some statistics to work with

Here is a group of scores on a test out of 40.

• what patterns do you see?
  
  
• where should we start?
  
  
• take ten minutes, tell me everything you can about these numbers
  
  

What is the first thing you do when you get a bunch of marks?

What's first question students will ask you when you hand something back?

• work out the average
  
  
• but there are in fact three types of averages