# 6.4: Activity 3 - Sampling the Past

- Page ID
- 74773

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Sampling strategy |
Brief description |
---|---|

Simple random sample |
The number of units, or grid squares on a coordinate grid map, to be sampled is chosen using a random number generator from a number table, app, or website such as www.calculatorsoup.com/calculators/statistics/number-generator.php. |

Stratified random sample |
The area to be sampled is divided into natural zones and the number of units (grid squares) to sample is chosen using a random number generator to represent equally each type of natural zone. Thus, if 50% of the area is forested, 50% of the sampled units will be in forested areas. |

Systematic sample |
Sampling is conducted in equally and regularly spaced units, such as every third grid square. |

Stratified unaligned systematic sample |
The site is divided into an arbitrary number of equally sized zones, as determined by the researcher. A predetermined number of units in each zone are randomly selected for sampling. |

## Simple Random Sample

Letters | Numbers |
---|---|

## Stratified Random Sample

## Systematic Sample

## Stratified Unaligned Systematic Sample

Zone 1 (rows 1–5) | Zone 2 (rows 6–10) | Zone 3 (rows 11–15) | |||||

Letters | Numbers | Letters | Numbers | Letters | Numbers | ||