Statistical Models, Data, Classes – AS Maths Revision – Statistics (S1)

Why Create a Statistical Model?

  • You need to find solutions / answers to a problem
  • You could try it out for real, but that would be expensive and time-consuming
  • Using a mathematical model is therefore cheaper and quicker
  • You can change and analyse the variables easily (a lot easier than putting a prototype back to how it was originally, then testing it under some different conditions, anyway)
  • However… models are only simplifications, and they might not work under certain conditions!
    NASA Sunspot Number Predictions for Solar cycl...
    NASA Sunspot Number Predictions for Solar cycle 23 and 24 (Photo credit: Wikipedia)

How to Create a Statistical Model

  1. Observe the thing you want to model, identifying what you want to predict
  2. Suggest a model
  3. Use the model to predict some stuff
  4. Collect data to test the predictions
  5. Compare the predictions with the results
  6. Refine the model if necessary
  7. GOTO 3 (or 4)

Data Definitions

  • Data – Measurements, observations, facts… (the actual bits – the numbers)
  • Variables – Things that are measured or observed (mass, age, score in Statistics exam…)
  • Qualitative data is non-numerical data
  • Quantitative data is numerical data
  • Discrete data can only take certain values (integers only, for example)
  • Continuous data can take any value (within a realistic range, anyway)

Classes

  • Classes are groups data can be in
  • They’re what you get from saying “0 to 10 here, 10 to 20 here…”, etc.
  • The class boundaries are the… boundaries… of the class
  • The mid-point is… the point at the middle of the group (the mean of the two boundaries)
  • The class width is… the width of the class: the upper boundary minus the lower boundary
Advertisements

About Matt

I like writing, filmmaking, programming and gaming, and prefer creating media to consuming it. On the topic of consumption, I'm also a big fan of eating.
This entry was posted in AS Maths Revision, No Category and tagged , , , , , , , , , , . Bookmark the permalink.

Enter comment:

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s