91Ó°ÊÓ

Handwriting Versus Keyboard Writ ing. Do people who write by hand have a better memory of what they write than those who write using a keyboard? To test this, researchers had 36 participant s in a study write down a long list of words read out loud to them. They were then asked to put aside their list and try to recall as many of the words as possible. Two methods of writing down words were used. One was using a blue-ink regular ball point pen and a notepad. The other was using a laptop equipped with a full-size keyboard. The number of words correctly recalled was the response. 31 a. Out line a completely randomized design to learn the effect of method of writing words on number of words correctly recalled. b. Describe in detail the design of a matched pairs experiment, using the same 36 subjects, in which each subject serves as his or her own control. c. The researchers reported that word recall was better when the words were written down on a notepad, and the result was statistically significant. What does statistically significant mean in describing the outcome of this study?

Step by step solution

01

Understanding Completely Randomized Design

A completely randomized design implies randomly assigning subjects to different treatment groups without regard to any other factors. In this experiment, you will randomly assign the 36 participants to two groups. Group 1 will write words using a pen and notepad, while Group 2 will use a laptop. Each group will comprise 18 participants. After writing, measure the number of words each participant can recall, then compare the results between the two groups to assess the effect of writing method.

02

Developing a Matched Pairs Design

A matched pairs design uses paired subjects or the same subjects for both treatment conditions. Here, each of the 36 participants will write words twice on different occasions: once using a pen and notepad, and once using a laptop. The order of treatments should be randomized (e.g., half the participants write by hand first, then use the keyboard, and vice versa). This ensures that each participant serves as their own control, minimizing variability that results from individual differences.

03

Defining Statistical Significance

Statistical significance in this context means that the observed effect (better recall when words are written by hand) is unlikely to have occurred by chance. A statistically significant result has typically passed a threshold (usually a p-value < 0.05) indicating that there is a less than 5% probability that the observed difference in word recall is due to random chance rather than the writing method itself.

Unlock Step-by-Step Solutions & Ace Your Exams!

• Full Textbook Solutions

  Get detailed explanations and key concepts

• Unlimited Al creation

  Al flashcards, explanations, exams and more...

• Ads-free access

  To over 500 millions flashcards

• Money-back guarantee

  We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Completely Randomized Design

In experimental research, the completely randomized design is a straightforward and common approach to assigning subjects to different treatments. The essence of this design is that each participant is randomly assigned to one of the different treatment groups, ensuring that each group receives no advantage or disadvantage from any prior factors. In the context of our handwriting versus keyboard experiment, we have 36 participants.

With a completely randomized design:

• The participants are randomly divided into two equal groups of 18.
• Group 1 uses a pen and notepad.
• Group 2 uses a laptop with a keyboard.

After each group completes the task, the number of words they recall is measured and compared. This design balances unknown variables between groups only by chance, aiming to have equivalent groups apart from the actual treatment given. Any difference in recall might then be attributed to the method used, assuming successful randomization and no systematic bias. This randomness gives the experiment validity against external influences.

Matched Pairs Experiment

In a matched pairs experiment, each participant receives both treatments, allowing them to act as their own control. This design is particularly useful in minimizing the effects of individual differences on the experimental outcomes.

For our study, each of the 36 participants is involved in both treatment conditions, which means:

• Each participant writes using a pen and notepad once and a laptop with a keyboard another time.
• The order of treatments is randomized. Half of the participants use the pen and notepad first, then the keyboard, and vice versa for the other half.
• This method reduces the variability caused by individual difference as the same person undergoes both treatments.

By using this design, each person's recall performance in one treatment can be directly compared to their performance in the other. This self-comparison increases the experiment's sensitivity to detect real differences in recall ability between handwriting and typing. Despite the increased power, ensuring proper randomization of sequence is crucial, to alleviate potential biases like fatigue or learning effects.

Statistical Significance

Statistical significance is a critical concept in experiments, serving as an indicator of whether the outcomes observed are likely due to the treatment effect or merely due to chance. When a result is statistically significant, it implies the differences observed are not random and are instead meaningful.

In the handwriting versus keyboard study, researchers reported a statistically significant result favoring handwriting. In scientific terms, this usually means:

• The probability (p-value) of observing the given difference, or one more extreme, purely by chance, is below a set threshold, commonly 0.05.
• In this study, a statistically significant result means there's strong evidence that handwriting improves memory recall compared to typing.
• While statistical significance doesn't measure the size or importance of the effect, it does suggest reliability of the result beyond random chance.

This significance level provides confidence in asserting that the writing method genuinely influences recall ability. However, understanding effect size and real-world impact should also accompany such statistical findings to offer a full picture of the results' practical importance.