Case Study: Final Graph and Overview

Weekly Summary

Though there were two non-consecutive weeks in the intervention which showed a drop in scores, these incidents did not qualify for a change in the intervention according to the evaluation plan. Also, classroom and home circumstances must be considered, as Justin saw several changes which could have contributed to his disruptions in scores. For the seven week period identified as “baseline,” Justin’s class remained consistent in weekly academics, including reading exercises. Also, during baseline, Justin’s home life and eating and sleeping habits showed no signs of abnormality.

First Week

With the onset of the intervention, however, this consistency of everyday academic life ended. The week after Justin’s first week of intervention, and thus before his first probe after the intervention began, Justin’s class participated in the state’s mandatory testing of students. This week also held a snow day, so the time spent in testing was even more intense. Teacher report shows that no reading (or other) instruction was held this week. This was also his year long classroom teacher’s last week with her students. Even with these circumstances, Justin showed a 6.8 percent accuracy score improvement over the previous week. This was the first time since the project began that Justin showed an improvement for a third consecutive probe.

Second Week

Justin’s reading accuracy score following the second week of intervention dropped to 51.3%, a 10.5 percent accuracy decrease. Justin’s scores had dropped twice during the baseline period, with decreases of 21.6% and 22.5% for the two. The 10.5% decrease in scores after the second week of intervention was less than half of the two previous decreases in scoring. Additionally, this second week was the first week with the new teacher Justin would have for the remainder of the school year. This teacher reports that she was absent on the Tuesday before the probe was taken, and that because of the chaos of entering a classroom near the end of a school year, very little academic, and no reading instruction had been accomplished. This marked the second week in a row in which Justin had not had any reading instruction in the classroom. Additionally, Justin appeared extremely distracted this week. Justin is normally very talkative, yet cooperative. He is not known to complain and always seems to enjoy his sessions with the intervention tutor. This week, Justin complained often about being extremely hungry, reported that he had not had breakfast, and that he had forgotten his snack. Snack time usually occurs thirty minutes before our meetings. Considering the unique classroom circumstances and Justin’s not previously seen distractedness, no changes in the intervention were arranged. Considering Justin’s past score variability, and the fact that he had just undergone three consecutive weeks of increasing scores, a slight downturn was not considered abnormal.

Third Week

The scores reflecting his third week of intervention again showed an increase. His score went to 67.6 from his score of 51.3 the week before. This was the second highest score Justin received in the eleven weeks he was seen by the writing instructor. The new teacher reports that she felt more at ease this week and that reading instruction had occurred. Justin, however, again reported not eating breakfast and said that when he went to bring a snack for school, that his mother told him that he couldn’t be taking snacks to school at this time. When asked, Justin reports that he had always been permitted to bring snacks in the past, and that until recently, he normally always ate breakfast. A school mate had given him part of his snack, so Justin did not report being excessively hungry today.

Fourth Week

Reading accuracy score results for his fourth and last week of intervention showed a 3.7% decrease. Still, this was one of his highest scores seen in the eleven week period. Though classroom activities were reported as being normal, Justin did report skipping breakfast and snack this week. He complained of being hungry and was further distracted because he feared missing an upcoming school activity. His school was participating in COSI Hands-On Science Centers and Justin’s class was scheduled to leave for the event as soon as Justin returned. Additionally, there was only one day of school remaining before spring break. Justin was clearly excited about not having to come to school for the next week.

Results Evaluation

Original Goal

Several methods were discussed as possible indicators of intervention success. First, there was the original goal of having Justin read at a 61.3% accuracy level. The mean of his four weeks of intervention was 61.4, and his last two intervention scores were 67.6 and 63.9, respectively, showing that Justin met this goal.

Trend line

It was decided that an intervention trend line above 2.0 would show a (moderately) successful intervention. The baseline trend line was 1.96. The intervention trend line was 2.03. It should be noted that the intervention trend line must be interpreted with caution, as there were less than six data points covered in the span. With this method, Justin’s intervention was successful. Also, ceiling effects show a limitation to this method of evaluation.

Comparing Means

The mean for the seven weeks of baseline was 55.8. The mean for the four weeks of intervention was 61.4, a 5.6 increase. However, if looking at only the four weeks previous to the intervention, the mean is 61.4, showing no change from the four weeks before intervention to the four weeks after intervention. This is because of Justin’s high score of 76.6 on 19 February, 2004. Because Justin had highly variable scores during the baseline phase, his baseline mean with the high and low scores removed was examined. This gave a new baseline mean of 55.1, which is nearly identical to the seven week mean without scores removed. Overall, it appears that the mean for intervention was higher, and visually, the scores appear slightly more stable than the baseline scores. This leads to the idea that the intervention was successful.

Effect Size

The intervention showed an effect size of 0.44. Effect size was calculated using the “standardized difference approach” as follows: [(Baseline Mean – Intervention Mean) / (SD of Baseline)] (Shernoff, Kratochwill, & Stoiber, 2002).

Conclusions

Overall, it appears that the intervention was effective. This is especially true when the circumstances of the intervention period are considered. However, Justin’s scores showed a general trend of increase and growing stability over the course of the project. As agreed upon by his classroom teacher, this could be because the entire process offered Justin extra attention in reading skills and the opportunity to practice with feedback. Regardless of the specific reason, it appears that Justin is a better reader because he participated in the intervention/case study process.

References

Shernoff, E. S., Kratochwill, T. R., & Stoiber, K.C. (2002). Evidence-based interventions in school psychology: An illustration of task force coding criteria using single-participant research design. School Psychology Quarterly, 17, 390-422.

Filed under: EDC 514-515 Academic Assessment for Intervention
Copyright: April, 2004 - David Profitt