STAT 1034 Lecture Notes - Lecture 3: Dependent And Independent Variables, Stratified Sampling, Simple Random Sample
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Each treatment is a combination of specific values (called levels) of each of the factors: ex: the ability to grow in shade may help pines found in the dry desserts of. Researchers planted 40 pine seedlings in a greenhouse in either full light, or 5% reduced light. It controls: temp, humidity, soil type, h2o type. Day 14 (9/27): experiments can be prone to bias if it systematically favors certain outcomes. To avoid bias use a double blind experiment. In a block design, the random assignment of units to treatments is carried out separately within each block: matched pairs: a form of blocking for comparing just two treatments. The idea is that matched pairs are more similar than unmatched pairs, so comparing responses within a number of pairs is more efficient that comparing groups: 3. 3 sampling design. Most methods use impersonal chance to select the sample (probability sampling methods: the basic probability sample is a simple random sample (srs).
