Statistical significance of ultrasound content knowledge in sonography training

Pre-Post Test Knowledge of Ultrasound Content Knowledge for Sonographers

When an investigative research study ins set up on the basis of a pre and post testing situation the investigator is afforded the opportunity not only to determine differences in mean test scores for the before and after criterion but also establish whether or not there exists a relationship between the pre and post test situation. The latter statistical process is known as a correlation study. In addition the investigator is also able, on an individual participant basis, able to determine wherein each individual places with respect to the average scores on a pre-test basis and on a post-test basis in respect to the group average. This calculation is known as a Z Score.

Descriptive Statistics Results

Pre-Test Ability to Detect Abnormalities

Parameter

Value

Mean

SD

SEM

Median

B. Post-Test Ability to Detect Abnormalities

Parameter

Value

Mean

SD

SEM

Median

C. Mean and Median Graphic Presentation of Differences

Between Pre-test and Post-Test Results

Conclusion: On the basis of the raw data (i.e., non-statistical significant difference) there appears to be a slight increase in ultrasound content knowledge as result of individuals participating in the academic course. Whether or not the reported difference is statistically significant is not known from a review of the raw data. In addition, the conclusion can be drawn that the variability of ultrasound knowledge is more variable before the course vs. after the course.

D. Statistical Analysis of Raw Data visa via "t" Test Calculation:

value and statistical significance:

The two-tailed P. value equals 0.0033

By conventional criteria, this difference is considered to be very statistically significant.

Confidence interval:

The mean of Group One minus Group Two equals -5.694852

95% confidence interval of this difference: From -9.458031 to -1.931672

Intermediate values used in calculations:

t = 2.9968 df = 118 standard error of difference = 1.900

Observations

Conclusion: A required correlation value of at least 0.273 is needed to be able to establish a statistical significant relationship between pre-test and post-test results with respect to the having had participated in a ultrasound course emphasizing content knowledge. The received value of 0.500 far exceeds the critical value needed and the conclusion drawn is that a statistically significant relation ship exists between the content knowledge level of the pre-test and post-test ultrasound content knowledge.