Question

It is thought that communication mode influences academic, speech, language, and auditory outcomes. To investigate differences in speech production, (GF-Post), the participants were divided into three groups: (1) Those with CIs using listening and spoken language, (2) Those with CIs using total communication, and (3) Those without CIs using total communication.

A) What inferential test should the researchers use to test for differences in speech production at the end of the study?

B)Name the independent and dependent variables and their scales of measurement. Include justification.

Below are summary statistics. Complete the table, parts B and D of the ABCD process, conclude the analysis, and draw warranted conclusions.

GF-Post Means for Communication Groups
	Group 1 (CI, LSL)	Group 2 (CI, TC)	Group 3 (No CI, TC)
Mean	89.8	76.4	67.8
N	11	5	16

           

ANOVA Summary Table
Source	df	MS	F
Between/Groups		27.8	Fcrit
Within/Error		8.12	Fobt

        

C)Do the results require the use of post-hoc tests? Why or why not?

If the results of the analysis of variance require the use of post-hoc tests, employ Fisher’s LSD to determine which groups differ

Answer 1

Given that, Participate devided into following 3 goups of speech production.

1) (CI , LSL) 2) ( CI , TC ) 3) ( No CI , TC )

A)

Here we use ANOVA test for differences in speech production at the end of the study. We calculate F critical value by using formula

  

And comapire F-Critical value with F-obt, And if F-critical greater than F- obt then we reject Null hypothesis. Where Hypothesis is as follows.

Null Hypothesis : Mean value of all 3 independent goups are equal

Alternative Hypothesis : Mean value of all 3 independent goups are not equal.

And we see below F table for F-obt. value.

B)

Here we check differences between Speech Production , We take a test of 100 marks. So scale of measurement of variables is mark.

here all are independent variables are as

1) CIs using listening and spoken language

2)  CIs using total communication

3) without CIs using total communication

From given information we complete the incomplete ANOVA table as

Source	df	MS	F
Between Group	3-1 = 2	27.8
Within Group	32 - 3 = 29	8.12
Total	32 - 1 =31

From above f table , F-obt = F_{(2,29 , 0.05)} = 3.33

Here, we see that F-Critical > F-obt. So we reject null hypothesis. That we conclude that means of 3 groups are not same.

c) Here means of group are not equal, So we use Post-hoc t-test for cheking which 2 groups are differ.

Where,

We know  that MSE is another name for MS Within.

Group		LSD(i , j)
(CI , LSL) & ( CI , TC)	2.8438	4.712
(CI , LSL) & ( No CI , TC)	2.0651	10.6531
(CI , TC) & ( No CI , TC)	2.7014	3.1835

And T_Critical = T_{(29 , 0.05)} = 1.699 .... For one tail

Here we see that all LSD values of 3 groups combination are greater than 1.699. So we reject null hypothesis.

That is we conclude that, All 3 goups are differ from each other.