Question

The head of the quality control department a printing company would like to carry out an experiment to. determine which of three different glues results in the greatest binding strength. Although they are not of interest in the current investigation, other factors thought to affect binding strength are the number of pages in the book and whether the book is being bound as a paperback or a hardback. a. What is the response variable in this experiment? b. What factor will determine the experimental conditions? c. What two extraneous factors are mentioned in the problem description? Are there other extraneous factors that should be considered?

Short answer

a. The response variable is the binding strength. b. The type of glue is the factor that will determine the experimental conditions. c. The two extraneous factors mentioned in the problem are the number of pages in the book and whether the book is being bound as a paperback or a hardback. Always consider that there might be additional extraneous factors.

Step-by-step solution

Identify the Response Variable

The response variable in an experiment is the variable that is measured as an outcome. It's the variable that the experimenters are interested in studying. In this particular case, the response variable is the 'binding strength'. This is identified from the phrase 'determine which of three different glues results in the greatest binding strength', implying that binding strength is the desired outcome to measure.

Identify the Factor Determining the Experimental Conditions

Experimental conditions are determined by the factors that the experimenters intentionally vary. In this scenario, the factor determining the experimental conditions is the 'type of glue' used. This is because the experiment aims to find out 'which of three different glues results in the greatest binding strength'

Identify the Extraneous Factors

Extraneous factors are variables that are not of interest in the current study, but may impact the response variable. In the problem description, two extraneous factors are mentioned: 'the number of pages in the book' and 'whether the book is being bound as a paperback or a hardback'. There can be other extraneous factors as well such as the thickness of the pages, the type and quality of paper used, conditions where books are kept etc. These factors could potentially affect the binding strength of a book but are not the subject of this experiment.

Key concepts

Response Variable

In an experiment, understanding the role of the response variable is crucial to both the design and analysis. It is essentially the main outcome that the researchers aim to explore or measure. Simplifying it with an example, when a printing company wishes to determine the most effective glue for bookbinding, the response variable is the 'binding strength'. The experiment is set up with the intention of altering other variables to observe the effect on this response variable. This variable's data is gathered and analyzed to draw conclusions. It's akin to the lead character in a play—the one who captures the spotlight and around whom the story revolves.

Ensuring the response variable's measurements are accurate and reliable is vital. This could entail utilizing precise instruments or applying consistent measurement techniques. If the binding strength were measured with inconsistent pressure or time intervals, it would blur the clarity of the outcome. It's much like a chef tasting a recipe at uniform stages to ensure the desired flavor is achieved. A clear understanding and careful measurement of the response variable are paramount for any conclusive findings in an experiment.

Experimental Conditions

The experimental conditions are the scenarios under which the experiment is conducted and are defined by the variables that experimenters deliberately change. Imagine them as the different paths in a maze, each leading to potentially different outcomes. In the case of the printing company, the type of glue used for bookbinding creates distinct experimental conditions. Three separate glue types offer three variations of these conditions—akin to testing different fuel types in a car to compare efficiency.

Every experimental condition should aim for homogeneity in all aspects except for the variable being tested to ensure that observed differences in the response variable are attributable to the variable under study, not other noise. Like altering one ingredient in a cookie recipe at a time, this approach helps determine which particular change improves the taste. A meticulously controlled experiment requires that any other variables that might interfere are held constant; otherwise, it becomes difficult to attribute differences in the response variable to the experimental conditions alone.

Extraneous Factors

While focal variables are controlled and measured, there is a myriad of extraneous factors that can sneak into an experiment. These factors are like uninvited guests at a party, potentially disrupting the intended dynamics. They are not the primary interest of the research but can inadvertently influence the outcome. As mentioned, in the binding strength experiment, the number of pages and the bookbinding type (paperback or hardback) represent such extraneous variables.

Other potential extraneous factors could include environmental conditions such as humidity or temperature, materials' quality (like paper type), and the binding machine's precision. These are like the various background noises that might distract during a music performance. In some cases, if these factors are neglected, they could produce misleading results, much as background noise might be misconstrued for music. Consideration of these variables is paramount, as they could otherwise introduce bias or noise into the experimental results, like an untuned instrument affecting an orchestra's harmony. Handling these factors might involve randomization, creating similar conditions across experimental groups, or including them as controlled variables in the design if their influence is significant.