# T-test Coordination

'Girls and Boys - who are the most coordinated? '

Divide yourself into two groups: boys and girls (by sex or by gender) - or any other two groups your class suspects, or is unsure, demonstrates differences in coordination.

Throw the ball (your teacher may give you a whole variety of different balls to try!) against a wall.

One-handed throws.

Whatever hand you throw it with you must catch it in the opposite hand.

Technically, the T-test is for continuous data (e.g. the time, in seconds, it takes you to fully complete 30 clean catches), but provided **samples are large**, it could be used for discrete data as the t-test is a test on the **sample means** i.e. you can **count number of catches **in a set period of time e.g. **1 minute. **

**Penalties **for not catching the ball can be included e.g. +5 seconds for each catch missed! but the ball will bounce around the room/space and cost you time anyway!

See below for details & ways you can organise this activity. See the slides and practice question here for more details on the calculating the T-test values and its assumptions.

### Resources

**The Game: class only or whole school data collection (see "sampling" below):**

Under-arm and Over-arm throws exclusively or a mix of whatever participants prefer (probably best to leave them the option!)

#### Sampling considerations - Whole school data collection!

This activity can tie in well to a CAS "staying healthy" global issue project etc. or cross-curricula link with sports etc.

Rather than only use the class, IB students can organise, the week before this lesson, collecting data from the whole school e.g. at lunch times/recreation breaks, in return for a sweet (if they need to attract some customers to begin with, but likely it won't be necessary (ToK: ethics!)), boys and girls in the playground come and complete the test and write down their age (in years & months if possible), and the time to complete 30 throws/number of throws in 1 minute: one handed catches and throws and catching and throwing in opposite hands etc See "The Game" above, and "Description" below - either/both can be printed and laminated for students to read whilst waiting in the queue. Why not have some "practice walls" ready for students whilst they wait!

**Stratified**Sampling - are the students who participated representative of the entire school/town/population?**Random**sampling - Was the data collected in only area where mostly music students hang-out/ art students / sporty students hang out etc.**Quota sampling**- does your sample include an equal number of boys and girls? Is there an equal number of boys and girls in the country you are in? The world?

**Data Collection**

### Syllabus links

**Standard level: **SL4.11 T-test and SL4.1 Concepts of population, sample, random sample, discrete and continuous data, Reliability of data sources and bias in sampling.

**Higher level: **AHL 4.12 Data collection methods

### Description

- Divide yourself into two groups: boys and girls (by sex or by gender - or any other two groups your class suspects, or is unsure, demonstrates differences in coordination.
- Throw the ball (your teacher may give you a whole variety of different balls to try!) against a wall.
- One-handed throws.
- Whatever hand you throw it with you must catch it in the opposite hand.
- Technically, the T-test is for
**continuous**data (e.g. the time, in seconds, it takes you to fully complete 30 clean catches), but provided**samples are large**, it could be used for discrete data as the t-test is a test on the**sample means**i.e. you can**count number of catches**in a set period of time e.g.**1 minute.**See below! **Penalties**for not catching the ball can be included e.g. +5 seconds for each catch missed! but the ball will bounce around the room/space and cost you time anyway!