×

### Let's log you in.

or

Don't have a StudySoup account? Create one here!

×

or

## Wednesday March 9th Notes

by: Christine Notetaker

19

0

7

# Wednesday March 9th Notes Comm 3000Q

Christine Notetaker
UCONN

Enter your email below and we will instantly email you these Notes for Research Methods in Communication

(Limited time offer)

Unlock FREE Class Notes

### Enter your email below to receive Research Methods in Communication notes

Everyone needs better class notes. Enter your email and we will send you notes for this class for free.

Statistics in the research design
COURSE
Research Methods in Communication
PROF.
Bryan Vanco
TYPE
Class Notes
PAGES
7
WORDS
KARMA
Free

## Popular in Communication Studies

This 7 page Class Notes was uploaded by Christine Notetaker on Wednesday March 9, 2016. The Class Notes belongs to Comm 3000Q at University of Connecticut taught by Bryan Vanco in Spring 2016. Since its upload, it has received 19 views. For similar materials see Research Methods in Communication in Communication Studies at University of Connecticut.

×

## Reviews for Wednesday March 9th Notes

×

×

### What is Karma?

#### You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 03/09/16
Thursday, May 19, y Calculating Statistics  Visualizing: Frequency Table ­ frequency table—a grouping of qualitative data into mutually exclusive classes  showing the number of observations in each class  Car Type Number of Cars Foreign 30 Domestic 60 ­ Bar Chart—a graph in which the classes are reported on the horizontal axis and the  class frequencies on the vertical axis.  The class frequencies are proportion to the  60 45 30 Foreign domestic 15 0 number of cars height of the bars 1 Thursday, May 19, y Relative Class Frequencies ­ Class frequencies can be converted to relative class frequencies to show the fraction  of the total number of observations in each class  Constructing a Frequency Table ­ steps  • decide on the number of classes  ­ based on: the amount of data, the range of the data, and making sure that all  aspects are represented  • determine interval or width  ­ until you reach the max  ­ ALL must be the SAME size  • Set the individual class limits  • tally the vehicle selling price into the classes  • count the number of items in each class  Relative Frequency Distribution ­ To convert a frequency distribution to a relative frequency distribution each of the  class frequencies is divided by the total number of observations  • for example: 80 cars are sold  • 8 are sold in the \$15,000­\$18,000 range  • 8/80=0.100  2 Thursday, May 19, y Visualizing data: Histograms ­ Similar to a bar chart showing the distribution of qualitative data the classes are  marked on the horizontal axis and the class frequency on the vertical axis.  The class  frequencies are represented by the heights of the bars  ­ you are able to draw a distribution around the histogram  ­ the example from the slides (see this for the information below)  • it is unimodal (there is only one mode)  • it is slightly positively skewed  Visualizing Date: Frequency Polygon ­ also shows the shape of the distribution of the data (it is similar to the histogram)  ­ consists of line segments connecting the points formed by the intersections of the class midpoints (of each of the categories) and the class frequencies  ­ SEE THE SLIDE IN THE POWERPOINT FOR THE WAY THAT THIS LOOKS  Measures of dispersion ­ dispersion: how scores/data points individually vary from the mean  • also known as variability  ­ need to fully describe the distribution  • group A: 5, 5, 6, 4, 4, 0, 6 (Mean=4.29) • Group B: 1, 10, 0, 1, 10, 3, 5 (Mean=4.29) • The means are the same but the standard deviations would be different due to the  outliers  ­ always reported in conjunction with a measure of central tendency  • typically mean and standard deviation are reported together  3 Thursday, May 19, y ­ provided information about validity of scores in a dataset  Dispersion: Range ­ Value that is calculated by subtracting the lower score from the higher score  ­ gives a general sense of how the data is spread across the distribution  ­ VERY sensitive to outliers  Dispersion: Deviation ­ Amount that anyone score deviates from the sample mean  ­ zero sum principle—sum of the deviations will always be 0 with rounding  ­ sum of the devotions (from lecture) =0.03 (rounds to 0)  23 ­4.33 24 ­3.33 26 ­1.33 27 ­0.33 27 ­0.33 27 ­0.33 30 2.67 23 ­4.33 18.75 31 3.67 24 ­3.33 11.09 31 3.67 26 ­1.33 1.77 27 ­0.33 0.11 27 ­0.33 0.11 27 ­0.33 0.11 Sum of Squares ­ 30 2.67 7.13 sum of the deviations  31 3.67 13.47 ­ difficult to interpret  31 3.67 13.47 ­ solves the problem of the zero sum principle  4 Thursday, May 19, y • we no longer get a zero but something we can quantify  ­ SS= ∑(X­x(bar))^2 = 66.00 Dispersion: Variance ­ Sum of the squares divided by the number of cases  ­ higher variance= more variability and dispersion in the sample  ­ difficult to interpret because it si still in “squared terms”  ­ Variance = ∑(X­xbar)^2/ N  ­ Variance= 66.00/9 = 7.33 (this is still squared)  Dispersion: Standard Deviation ­ It is the square root (√) of the variance  ­ standardized average amount of dispersion in the data set  ­ larger=scores differ a great deal from the average  5 Thursday, May 19, y ­ smaller=scores are close to the average  ­ 0= all scores are the same  ­ SD=√Variance  ­ SD=√7.33  ­ SD= 2.71 ­ Full equation for SD= √(∑(X­xbar)^2)/(N) Steps in Calculating SD ­ Using the mean, calculate the deviation score for each item  ­ square each deviation score and sum them (SS)  ­ divide SS by the number of cases (Variance)  ­ √ of the result  Z-Scores ­ Alone a raw score says little about its position in a distribution  ­ solution: transform the original raw more meaningful and information  STANDARDIZED  • researchers can report how many SD a particular score is above or below the  mean • NOW WE CAN COMPARE SCORES ACROSS DIFFERENT GROUPS WTH  DIFFERENT MEANS  ­ Z­Score transforms score into a signed number (either positive or negative)  •  tells whether the score is about or below the mean  • tells the distance between the scores and the mean in units in the SD  6 Thursday, May 19, y 23 ­1.6 24 ­1.23 26 ­0.49 27 ­0.12 27 ­0.12 27 ­0.12 30 0.99 31 1.35 31 1.35 • 7

×

×

### BOOM! Enjoy Your Free Notes!

×

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

## Why people love StudySoup

Steve Martinelli UC Los Angeles

#### "There's no way I would have passed my Organic Chemistry class this semester without the notes and study guides I got from StudySoup."

Janice Dongeun University of Washington

#### "I used the money I made selling my notes & study guides to pay for spring break in Olympia, Washington...which was Sweet!"

Bentley McCaw University of Florida

Forbes

#### "Their 'Elite Notetakers' are making over \$1,200/month in sales by creating high quality content that helps their classmates in a time of need."

Become an Elite Notetaker and start selling your notes online!
×

### Refund Policy

#### STUDYSOUP CANCELLATION POLICY

All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email support@studysoup.com

#### STUDYSOUP REFUND POLICY

StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here: support@studysoup.com

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to support@studysoup.com