Design post-test

ECASS-II was designed to test a lower dose of rt-PA (0.9 mg/kg) during the same 0-6-hours time period after stroke onset, using similar inclusion criteria as in ECASS-I. ° The primary endpoint was the proportion with a favorable outcome on the mRS scale (defined as a score of 0 or 1). There was no difference in this outcome between rt-PA-treated and placebo controls (40% vs. 37%, p = 0.28). A separate analysis of the 158 subjects enrolled within 3 hours of stroke onset also showed no difference in the proportion with a favorable outcome (42% vs. 38%, p = 0.63) this result, however, must be treated with caution because in ECASS-II there was a substantially lower number of patients treated within 3 hours of stroke onset, compared to the 1995 NINDS rt-PA study. Parenchymal hematoma on post-treatment CT was seen in 12% of rt-PA-treated and 3% of placebo patients (p < 0.001). The 90-day mortality rate was 11 % for the rt-PA group and 11 % for the placebo group (p = 0.54). Protocol violations were much less frequent in ECASS-II compared to ECASS-I (9% vs. 18%), probably because of standardized training in CT interpretation at the study sites. 

There are two circumstances in which patients act as their own control crossover designs and pre-test, post-test designs. 

Fig. 7.3. Experiment designed to test if cross-fertilisation occurred with Hymenotepis diminuta. An Fi0 variant (with a testicular variation frequency of 31.7%) and a normal worm (variation frequency 2.5%) were simultaneously implanted into the duodenum of a rat. After worms became patent at 16 days post-implantation, the terminal gravid proglottides were removed and fed to separate groups of beetles. The resultant cysticercoids were fed to groups of 10 rats (one cysticercoid per rat). Analysis of the Ft worms revealed a statistically significant increase in the variation of frequency in the progeny of the normal worm and a statistically significant decrease in the variation frequency of the variant (Fi0) individual. (Compare xf= 17.6% with 4.1% in the implanted worms and with 2.5% in the original worms before implantation. (After Schiller, 1974.)...

Laird N (1983) Further comparative analyses of pre-test post-test research designs. The American Statistician 37 329-330. 

The results of the immediate and the 15-minute post-treatment study are listed in Tables 6 and 7. The data indicate that moisture level of the inoculum source can influence bacterial counts and impact results of studies designed to test efficacy of an antibacterial product. Furthermore, the consistency of the results declines as subjects acquire bacteria from sources other than a broth culture. Because consumers are often exposed to bacteria by touching contaminated objects, use of a broth inoculate may not always be appropriate when assessing the... 

Other research questions are better suited to a design that uses both qualitative and quantitative methods. Mulford and Robinson (2) developed an instrument to measure the extent of students alternate conceptions about topics found in a traditional first semester general chemistry course. Initially, an instrument consisting of 18 free-response questions was piloted. Qualitative analysis of the responses allowed the researchers to develop a multiple-choice survey instrument with incorrect answers that reflected the conceptions of students. The survey was used in a pre-test and post-test format with general chemistry students and the results were analyzed quantitatively to document changes in alternate conceptions among the students. This study was well matched to a mixed methods design where qualitative methods were used to... 

The research design allowed for paired pre- and post-test measures on the affective and cognitive instruments. This also matched the design adopted for the associated pupil research study. Despite the fact that the first cohort completed their tests a year after the end of their main in-service programme, the overall attimde and cognition profiles of the two cohorts were very similar (Jarvis, Pell McKeon 2003). Consequently, for flie focus of this paper, the scores were pooled to allow for straightforward pre-test/post-test analyses. 

In this section we present findings from the pre- and post-tests completed by students following the designed teaching sequences, compared with baseline information from students in comparable classes in the same schools following the school s usual programme of instruction (where such information was available). Findings from both the Development and Transfer Phases are reported. 

The Web site also contains valuable progress-monitoring tools. Each chapter has a pre-test that you can take as an assessment before you take your in-class exam. Use the results of your pre-test to design a personalized learning plan to correct any deficiencies that remain. You then take a post-test to make sure you have mastered the material. 

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