Completely Randomized Design (CRD) PDF

STATISTICAL ANALYSIS FOR INDUSTRIAL ENGINEERING 2 DESIGN AND ANALYSIS OF SINGLE- FACTOR EXPERIMENTS COMPLETELY RANDOMIZED DESIGN COMPLETELY RANDOMIZED DESIGN A Complete Randomized Design (CRD) is a type of experimental design where all the experimental units (like plants, animals, o...

STATISTICAL ANALYSIS FOR INDUSTRIAL ENGINEERING 2 DESIGN AND ANALYSIS OF SINGLE- FACTOR EXPERIMENTS COMPLETELY RANDOMIZED DESIGN COMPLETELY RANDOMIZED DESIGN A Complete Randomized Design (CRD) is a type of experimental design where all the experimental units (like plants, animals, or subjects) are randomly assigned to different treatments or conditions. The term "random design" typically pertains to the approach where experimental units or treatments are assigned randomly to groups or conditions in order to eliminate bias and ensure that the results can be generalized COMPLETELY RANDOMIZED DESIGN Randomization DEFINITION OF TERMS Definition: The process of assigning experimental units to different treatments or conditions in a random manner. This helps to minimize the influence of confounding variables and ensures that the experiment's results are due to the treatment effect rather than any other systematic bias Randomized Control Trial (RCT) Definition: A type of experimental design where participants are randomly assigned to either a treatment group or a control group. RCTs are considered the gold standard in experimental research because random assignment helps control for confounding factors. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Experimental Unit Definition: The smallest unit of observation in an experiment. It is the unit that receives the treatment or intervention. In agricultural experiments, for example, an experimental unit might be a single plant or a plot of land. Treatment Definition: The specific intervention, condition, or procedure that is applied to the experimental units. A treatment could be a drug, an educational program, a different manufacturing process, etc. Control Group Definition: A group of experimental units that does not receive the treatment being tested, but instead receives a placebo, no treatment, or a standard treatment. The control group is used for comparison to determine the effect of the experimental treatment. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Random Effects Definition: Factors in a model that are assumed to be random and drawn from a probability distribution. These effects represent sources of variability that are not of primary interest but contribute to the overall variability in the data (e.g., individual differences in a population). Block Design Definition: A type of experimental design in which experimental units are grouped into blocks that are similar to each other, and then treatments are randomly assigned within each block. Blocking helps control for variability between blocks, improving the precision of the experiment. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Replication Definition: The repetition of an experimental condition or treatment within an experiment. Replication increases the reliability of the results and allows for better estimation of variability. Bias Definition: Systematic errors in the design, data collection, or analysis process that lead to inaccurate or skewed results. Randomization helps reduce bias by ensuring that treatments are assigned in an unbiased way. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Confounding Variables Definition: Variables that are related to both the treatment and the outcome, potentially distorting the observed relationship between them. Randomization helps minimize confounding by evenly distributing confounding variables across treatment groups. Statistical Significance Definition: A statistical measure that determines whether the observed effects in an experiment are likely due to chance or whether they reflect a true relationship. Randomization increases the likelihood that statistical tests will correctly assess the significance of treatment effects. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Stratified Random Sampling Definition: A sampling method in which the population is divided into distinct subgroups (strata) based on some characteristic, and then random samples are drawn from each stratum. This ensures that all relevant subgroups are properly represented in the sample Control of Variables Definition: The process of keeping all variables, except the independent variable being tested, constant in an experiment. Randomization helps control for variables that might otherwise confound the results. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Random Assignment Definition: The practice of assigning subjects or experimental units to different treatment groups using random methods (e.g., using a random number generator). This helps to ensure that each participant or unit has an equal chance of being assigned to any group. Sample Size Definition: The number of experimental units or subjects included in an experiment. A larger sample size increases the precision of the estimates and the power of statistical tests, which is important when randomization is used. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Sampling Error Definition: The difference between the sample estimate and the true population value. Random sampling or random design can help reduce sampling error by ensuring that the sample is representative of the population. Double-Blind Experiment Definition: An experimental design where neither the participants nor the experimenters know which treatment the participants are receiving. This helps to prevent bias in treatment administration and in outcome measurement. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS Placebo Effect Definition: A psychological phenomenon in which participants experience improvements in their condition simply because they believe they are receiving treatment, even when the treatment has no therapeutic effect. A placebo group can be used in randomized experiments to measure this effect. Factorial Design Definition: A type of experimental design where multiple factors (independent variables) are tested simultaneously to examine their individual and interactive effects on the outcome. Random assignment is often used within factorial designs to reduce bias and confounding. COMPLETELY RANDOMIZED DESIGN DEFINITION OF TERMS True Experimental Design Definition: An experimental design where random assignment to treatment groups is used, along with controlled conditions, to establish a cause-and-effect relationship. True experimental designs are contrasted with quasi-experimental designs, where randomization is not employed.