Abstract
This investigation used a multiple-probe-across-participants design to examine the effects of using a simultaneous prompting procedure to teach four secondary students with mild intellectual disabilities the employment task of caring for plants in a greenhouse. The instructor also embedded photosynthesis science content as nontargeted information within instructional trials on the task analysis. Following the intervention, all four participants achieved criterion on the employment task and increased their knowledge of core science content. Maintenance data indicated students retained both skills for up to 8 weeks following intervention. Implications for practice and suggestions for research are discussed.
Keywords
In recent years, there has been a shift in the curriculum of students with intellectual disability (ID) toward a standards-based curriculum and instruction in core content standards (Ayres, Lowrey, Douglas, & Sievers, 2011). Legal mandates have specified that all students in special education have access to the general education curriculum and participate in state and district assessment (Individuals With Disabilities Education Act [IDEA], 2004). These new regulations and emphasis on standards-based reform have led school districts and researchers to examine how to incorporate students with ID in the general education curriculum. In addition to regulations, analyses from the National Longitudinal Transition Survey (NLTS-2) indicate students with ID who received a functional curriculum in secondary school did not have better post-school outcomes than their peers who received instruction in a curriculum focusing on academics (Bouck, 2010).
Despite this push to incorporate more academics in the instruction of students with ID, practitioners still have an obligation to teach students skills needed in future environments. These skills may not necessarily be academic in nature (Ayres et al., 2011). There is a body of research that has focused on incorporating both functional and academic skills in the curriculum for students with ID (e.g., Bartholomew, Papay, McConnell, & Cease-Cook, 2015; Collins, Karl, Riggs, Galloway, & Hager, 2010).
Researchers have identified systematic instructional methods that are effective in teaching students functional skills, including the constant time delay (CTD), system of least prompts (SLP), and simultaneous prompting (SP) procedures (Collins, 2012). These instructional methods can be combined with video modeling or video prompting (e.g., Graves, Collins, Schuster, & Kleinert, 2005; Norman, Collins, & Schuster, 2001). Courtade, Spooner, and Browder (2007) conducted a literature review in which they examined the current research on teaching science to students with significant ID. Results showed systematic instructional procedures have been successful in teaching science content to students; however, more studies are needed to include broader content and skills that link to content standards. Recently, researchers have used these same response-prompting procedures to teach academic content in a meaningful way.
For example, Karl, Collins, Hager, and Ault (2013) taught reading, math, and science standards to secondary students with moderate ID using an SP procedure during a cooking activity. The students acquired vocabulary while reading recipes to create a shopping list, calculated percent while searching for discounted items from their shopping list, and learned the scientific principles of force while cooking (e.g., cracking eggs). In another example, Riggs, Collins, Kleinert, and Knight (2013) taught principles of heredity to secondary students with severe disabilities using a CTD procedure with multiple exemplars of applied functional examples. The functional examples included healthy habits (i.e., good nutrition, exercise, medical monitoring) when diseases (i.e., heart disease, diabetes, high blood pressure) are inherited while teaching examples of dominant (e.g., brown eyes) and recessive (e.g., blue eyes) traits. Finally, Creech-Galloway, Collins, Knight, and Bausch (2013) used an SP procedure with functional examples of real-life problems on an iPad to teach the Pythagorean Theorem to secondary students with moderate ID. Students learned to work problems using the Pythagorean Theorem in functional examples that included landscaping, making draperies, and building an entertainment cabinet. While this research has been conducted in classroom settings, additional research needs to be conducted teaching students skills in other settings, such as potential employment settings.
Because secondary students with ID need to learn both academic core content and the vocational skills needed for successful transition to adulthood, more research is needed on embedding academic content in a job-specific task in a vocational setting. The researchers implemented the current study in an on-campus greenhouse using an SP procedure. SP is a systematic instructional strategy where the prompt is given immediately following the task direction to insure a correct response; daily assessment probes are conducted to determine when a student has acquired a skill (Collins, 2012). SP results in nearly errorless learning and is, thus, appropriate for teaching a job skill (e.g., Maciag, Schuster, Collins, & Cooper, 2000).
The purpose of the current study was to evaluate the effects of embedding high school biology academic core content (photosynthesis) in teaching a potential employment skill (plant care) using an SP procedure in a greenhouse. Photosynthesis is required science core content (North Carolina Essential Standards Biology 4.2.1 Analyze photosynthesis and cellular respiration in terms of how energy is stored, released, and transferred within and between these systems; “North Carolina Essential Standards,” n.d.) in the state standards where this study took place. The researchers also embedded core content as nontargeted information while teaching the employment skill because research has shown that students will acquire at least some of this content, pairing core content with a functional skill makes the task more meaningful, and exposure to nontargeted information during instruction decreases instructional time that must be devoted to teaching it in the future (Fetko, Collins, Hage, & Spriggs, 2013; Riggs et al., 2013; Wolery, Schuster, & Collins, 2000). When teaching targeted information, a systematic instructional trial requires an antecedent, response, and consequence, with a prompt inserted to ensure a correct response. However, nontargeted information is presented to expose a student to content without providing direct instruction or requiring a response with the purpose of increasing the amount of content a student may acquire through repeated exposures (e.g., Collins, Hall, Branson, & Holder, 1999). The research questions in this study were as follows:
Method
Participants
Participants in this investigation included four secondary students with ID. Additional participants included the instructor and two reliability observers.
Student participants
The instructor identified four student participants with ID who were enrolled in an occupational course of study at a local secondary school. The occupational course of study is a state-approved sequence of courses that leads to a standard high school diploma. It consists of instruction in (a) all academic areas, including basic writing skills; (b) vocational skills; and (c) self-determination skills. According to teacher records, the students in the class were not working on grade level and had employment post-secondary goals (i.e., obtain part-time employment, work in a retail store, obtain employment in a music store, and work at Chick-fil-a).
Andrea was a 16-year-old Hispanic female in the 10th grade who received special education services in a resource room for science, math, and language arts and, according to the Woodcock Johnson III (Woodcock, Mather, McGrew, & Schrank, 2001), had a General Intelligence Ability (GIA) of 65. Maria was an 18-year-old Hispanic female in the 10th grade who received special education services in a resource room for science, math, and language arts and, according to the Woodcock Johnson III (Woodcock et al., 2001), had a GIA of 70. Raul was a 17-year-old Hispanic male in the 10th grade who received special education services in a resource room for math and language arts and, according to the Woodcock Johnson III (Woodcock et al., 2001), had a GIA of 62. Tobias was a 19-year-old African American male in the 12th grade who received special education services for science, math, language arts, and social studies and, according to the Woodcock Johnson III, had a GIA of 71. All students were included in general education for all other classes
Instructor and reliability observers
One of the researchers in this investigation also served as instructor and primary data collector. She was a former secondary teacher of students with disabilities and was a special education doctoral student at the time of the investigation. She also held bachelor’s and master’s degrees in special education. Two special education doctoral students conducted reliability checks.
Setting
The student participants attended a public high school in a suburban area in the southeastern United States. The intervention took place daily at a greenhouse located in the middle of the high school campus. The researchers selected this setting because job coaches had identified working with plants as an appropriate vocational skill for future employment, but the researchers did not have access to a community greenhouse on a daily basis. The dimensions of the greenhouse were 25 feet by 34 feet. The greenhouse housed a variety of types of plants on 13 tables with multiple plants hanging from the ceiling. A water hose was in the corner where the researcher was able to get water for the intervention that took place on an empty table in the greenhouse.
Materials
Materials used in this investigation included (a) data collection materials (i.e., task analytic data sheet, typed page with photosynthesis content questions, pencil), (b) supplies needed for plant care (i.e., pruning shears, two tablespoons of fertilizer per plant, watering canister, gloves), (c) a plant pot 14.75 inches in diameter, (d) four Aralia (Ming, Fabian, and Elegantissima) plants, and (e) a picture chart (see Figure 1) with the steps of photosynthesis and key phrases displayed.

Photosynthesis picture chart.
Data Collection
The primary dependent variable in this intervention was independent completion of each step of the task analysis for the targeted task of plant care (see Table 1). The instructor conducted a daily probe trial prior to instructional trials during each session. The instructor recorded the number of steps completed independently and correctly within a pre-specified time limit of 15 s for Steps 1, 3, 4, and 5 and 30 s for Step 2 of the task analysis during probe trials (not during training trials). To be counted as correct, students did not have to complete the steps of the task analysis in sequential order. The instructor wrote a plus for each correct response, a minus for each incorrect response, and a zero for each no response on the data collection form. The second dependent variable was the photosynthesis core content inserted as nontargeted information during instruction as measured by the number of questions students answered correctly on a six-question test (see Table 2) during pre- and post-intervention sessions. The instructor recorded data on nontargeted information by administering the pre-test on the first day of baseline data collection and then administering the post-test on the day after participants reached mastery on the task analysis.
Task Analysis for Plant Care With Embedded Photosynthesis Content.
Photosynthesis Content Knowledge Quiz.
Reliability
The researchers collected reliability data on interobserver agreement and treatment integrity. These are described in the following sections.
Interobserver reliability
One of two independent observers observed and collected reliability data during the baseline, intervention, and maintenance conditions for each dependent variable while sessions were occurring. Using an item-by-item process (Kazdin, 1982), researchers calculated interobserver agreement by dividing the total agreements by the total agreements plus disagreements and multiplying by 100. The researchers collected interobserver reliability data for 32% of the baseline sessions while the session was occurring. Mean interobserver reliability agreement for the baseline condition was 100% across participants. The researchers collected interobserver reliability data for 33% of the intervention sessions. Mean interobserver reliability agreement for the intervention condition was 97% across participants (range = 80%–100%). The researchers collected interobserver reliability data for 34% of the maintenance sessions. Mean interobserver reliability agreement for the maintenance condition was 100% across participants.
Researchers also collected interobserver reliability data for the photosynthesis core content while the assessment sessions were occurring. The experimenter collected interobserver reliability data for 32% of the baseline sessions as pre-intervention assessment was conducted and for 34% of the maintenance sessions as post-intervention assessment was conducted. Mean interobserver reliability agreement for both baseline and maintenance conditions was 100% across participants
Treatment integrity
To ensure treatment integrity of the intervention, a second observer used a checklist to record the implementation of the independent variable. The checklist included the experimenter giving the task direction (i.e., “What’s first/next?”), waiting 5 s for a response during probe trials or delivering an immediate prompt during training trials, delivering the appropriate consequence (e.g., praise plus instructive feedback), and pointing to the corresponding part of photosynthesis chart while stating core content. The researchers calculated treatment fidelity for 32% of the baseline sessions and for 33% of the intervention sessions using the point-by-point method developed by Billingsley, White, and Munson (1980). They calculated treatment integrity as the number of steps correctly implemented divided by the total number of planned steps multiplied by 100. Agreement on procedural integrity was 100% for all observed sessions.
Content validity data
A general education biology teacher approved the photosynthesis content knowledge test, stating it was consistent with the photosynthesis cycle taught in general education as part of the 10th-grade biology curriculum (i.e., vocabulary, definitions, and steps of the cycles). In addition, the instructor consulted staff with the city parks and recreation department on the steps used in the task analysis for plant care; they confirmed these steps were correct and gave guidance on how much fertilizer to use in the plants. Finally, the instructor timed the co-investigator of this study while she completed the steps of the task analysis to provide an indicator of an appropriate response interval for the students to complete each step on the task analysis.
Social validity data
Following the investigation, the researchers collected outcome validity using a three-item questionnaire with a yes/no response that asked the student participants about the study. The instructor verbally asked each student participant whether he or she enjoyed working in the greenhouse, whether they felt like they learned about photosynthesis, and whether they thought they would use the skill of plant care sometime in the future.
Experimental Design
The researchers used a multiple-probe-across-participants design to establish experimental control and a functional relationship in this investigation (Gast, 2010). They implemented this design in a time-lagged fashion across student participants to control for threats to internal validity. The first participant entered the intervention condition after data across three baseline probes were stable or in a downward trend. The first participant transitioned from intervention to maintenance upon reaching mastery criterion on the target skill (completing all five steps on the task analysis independently) for 3 days. The next participant entered intervention after the first participant completed the intervention. The investigation proceeded in this manner until all student participants reached criterion on the target skill.
Procedures
Pre-screening
Prior to intervention, the instructor conducted pre-screening to determine the ability of potential student participants to perform the steps of a task analysis to care for plants and to determine their ability to answer questions on the core content of photosynthesis. She tested these students to see whether they could verbally respond to questions and follow multi-step verbal directions. She also asked them how to care for a plant and questions about photosynthesis to determine participants who would benefit from the study.
Baseline condition
Baseline condition took place in the greenhouse. The instructor stood beside the student with all materials assembled in front of the student on an empty table. The instructor gained the student’s attention by stating his or her name. When the student made eye contact, the instructor gave the task direction, “What do you do to take care of the plant?” The instructor waited 5 s for student to begin the first step. If the student responded correctly, she again waited for each of the next step of the task analysis to be performed after asking, “Is there anything else you do?” If a student responded incorrectly or did not respond, the instructor counted the step as incorrect. Using a single opportunity format, the instructor ended the probe session on the steps of the analysis when a student did not respond or responded incorrectly. The instructor said, “Thank you for your hard work,” but did not provide any other prompting, feedback, or error correction. The instructor only conducted one probe trial per step per session during baseline condition.
For the photosynthesis content, the instructor verbally asked the students each of the six questions one at a time in a one-to-one format. If, after 5 s, the student did not respond or responded incorrectly, the instructor moved to the next question. The instructor did not provide students with any feedback on correct or incorrect responses.
Intervention
During intervention, the instructor implemented the SP procedure, consisting of daily probe trials on each step of the task analysis followed by daily training trials on each step of the task analysis. All intervention sessions took place in the greenhouse. The instructor stood beside the student with all materials assembled in front of the student on an empty table.
Every intervention session began by probing the student on the plant care task analysis following the same procedure used during baseline. During training trials, the instructor gained the attention of the student by stating his or her name and presenting the task direction, “What’s first to take care of the plant?” followed by immediately delivering a verbal prompt for the step of the task analysis (e.g., “Rotate the plant so it gets sunlight evenly.”). After the student completed the step, the instructor praised the student (e.g., “Good job!”) and then provided the nontargeted information for that step as instructive feedback (e.g., “You rotate the plant because the plant needs sunlight for energy to make food.”) while presenting a picture chart of the photosynthesis cycle and pointing to the corresponding part of the cycle. She did not require the student to respond to the nontargeted information. The instructor then asked, “What’s next?” and repeated the training procedure for each step of the task analysis (see Table 1.)
Maintenance
Following the final probe session in which the student demonstrated mastery by completing the five steps of the task analysis with 100% accuracy for three sessions (sessions did not have to be consecutive), the instructor conducted a maintenance probe session on caring for a plant in the same manner as a baseline probe session each week until every participant had completed intervention and had at least one maintenance session. The instructor eliminated praise after each student completed all steps with 100% accuracy after one maintenance probe.
Following intervention, the instructor gave the student participants a post-test on the photosynthesis content knowledge in the same manner at the pre-test. She continued to conduct probe sessions on the photosynthesis content for eight sessions for Andrea, six sessions for Maria, four sessions for Raul, and two sessions for Tobias.
Nontargeted Information Follow-Up
Following intervention, the instructor conducted direct instruction on the nontargeted information that students failed to acquire during direct instruction on plant care. This direct instruction also consisted of the SP procedure and took place in a one-to-one format in the students’ special education classroom. The instructor conducted daily probe trials prior to the training trials in the same manner as baseline sessions testing photosynthesis content knowledge.
During daily training trials, the instructor gained the attention of the student by stating his or her name and then asked each question from the photosynthesis quiz the students’ previously missed (e.g., “What makes the leaf green?”) followed by immediately stating the answer (e.g., “Chlorophyll.”). The instructor praised the student for a correct answer and corrected incorrect responses. The instructor conducted five trials per question during each session.
Results
All students reached 100% criterion on the steps of the plant care task analysis for 3 days and increased knowledge of the photosynthesis content standard. All four students demonstrated maintenance of all skills. Participant data on the plant care task analysis are presented in Figure 2.

The number steps of correct on independent probes on the plant care task analysis.
Acquisition of Targeted Skills
During baseline condition, Andrea completed one of five steps on the task analysis across sessions. During intervention, she met criterion (100%) on Day 2 of training and mastery (100% for 3 days) on Day 4 of training. During maintenance, the instructor collected data once per week for 8 weeks. Andrea completed five of five steps on the task analysis across all maintenance probe sessions.
During baseline condition, Maria completed one of five steps on the task analysis across sessions. During intervention, she met criterion (100%) on Day 2 of training and mastery (100% for 3 days) on Day 6 of training. During maintenance, the instructor collected data once per week for 6 weeks. Maria completed five of five steps on the task analysis across all maintenance probe sessions.
During baseline condition, Raul completed a mean of 0.75 (range = 0–1) steps on the task analysis. During intervention, he met criterion (100%) on Day 2 of training and mastery (100% for 3 days) on Day 5 of training. During maintenance, the instructor collected data once per week for 4 weeks. Raul completed five of five steps on the task analysis across all maintenance probe sessions.
During baseline condition, Tobias completed one of five steps on the task analysis across sessions. During intervention, he met criterion (100%) on Day 2 of training and mastery (100% for 3 days) on Day 6 of training. During maintenance, the instructor collected data once per week for 2 weeks. Tobias completed five of five steps on the task analysis across all maintenance probe sessions.
Acquisition of Nontargeted Information
The instructor gave the photosynthesis pre-test to each student participant on the first day of baseline data collection and administered the post-test to each student participant on the day after each reached mastery on the task analysis. On the photosynthesis content knowledge pre-test, Andrea answered two of six questions correctly, and she answered four of six questions correctly on the post-test. Because Andrea did not master nontargeted information on the post-test, the instructor conducted SP training to mastery (answering all six questions correctly for 3 days) before moving to maintenance condition. Following the use of the SP procedure for three sessions to directly teach the photosynthesis content, Andrea answered six of six questions correctly. When the instructor collected maintenance data 1 week after instruction, Andrea continued to answer six of six questions correctly.
On the photosynthesis content knowledge pre-test, Maria answered one of six questions correctly, and she answered five of six questions correctly on the post-test. Because Maria did not master nontargeted information on the post-test, the experimenter conducted SP training until she reached mastery (answering all six questions correctly for 3 days) before moving to maintenance condition. Following the use of the SP procedure for three sessions to directly teach the photosynthesis content, Maria answered six of six questions correctly. When the instructor collected maintenance data 1 week after instruction, Maria continued to answer six of six questions correctly.
On the photosynthesis content knowledge pre-test, Raul answered one of six questions correctly, and he answered four of six questions correctly on the post-test. Because Raul did not master nontargeted information on the post-test, the instructor conducted SP training until he reached mastery (answering all six questions correctly for 3 days) before moving to maintenance condition. Following use of the SP procedure for three sessions to directly teach the photosynthesis content, Raul answered six of six questions correctly. When the instructor collected maintenance data 1 week after instruction, Raul answered six of six questions correctly.
On the photosynthesis content knowledge pre-test, Tobias answered one of six questions correctly, and he answered five of six questions correctly on the post-test. Because Tobias did not master nontargeted information on the post-test, the instructor conducted SP training until he reached mastery (answering all six questions correctly for 3 days) before moving to maintenance condition. Following use of the SP procedure for three sessions to directly teach the photosynthesis content, Tobias answered six of six questions correctly. When the instructor collected maintenance data 1 week after instruction, Tobias continued to answer six of six questions correctly.
Social Validity Data
When asked whether they enjoyed working in the greenhouse, four student participants reported “yes.” When asked whether they felt like they learned about photosynthesis, four student participants reported “yes.” When asked whether they thought they would use the skill of plant care sometime in the future, three student participants reported “yes,” and one student participant reported “no.” Therefore, it can be concluded that the students perceived that embedding core content in a functional activity was a positive way to learn, and two of three had acquired a skill they thought they might use in the future.
Discussion
The purpose of this study was to evaluate the effects of teaching a functional employment skill (plant care) using an SP procedure while embedding academic core content (photosynthesis) in a vocational setting (greenhouse). The results of this study demonstrated a functional relationship between the intervention and mastery of the task analysis on plant care and an increase in knowledge of photosynthesis content embedded as nontargeted information, which is consistent with current literature. Previous studies demonstrated the effectiveness of using an SP procedure to teach a functional skill while embedding academic content such as teaching Pythagorean Theorem (Creech-Galloway et al., 2013); teaching science, math, and reading (Karl et al., 2013); and teaching heredity (Riggs et al., 2013).
While teachers now are required to provide access to grade-level academic curricula for all students, they also are responsible for teaching students with ID the functional skills they need to facilitate positive post-school outcomes (Ayres et al., 2011). The challenge of teaching both becomes more important as students get closer to leaving high school. Core content instruction also becomes more challenging at the high school level because the curriculum becomes more complex. Special education teachers are charged with teaching these complex core content concepts to students with ID. This investigation adds to the growing body of research on combining instruction on functional and core content and offers strategies to teachers for how they can successfully teach this to students with ID. This study also extends the research on embedding core content as nontargeted information in teaching functional skills through the use of systematic instructional procedures, thus combining the two in a meaningful way. In this case, the researchers embedded multiple pieces of nontargeted information in a way that corresponded to real-life applications.
The results demonstrated how efficient the SP procedure was by how quickly participants acquired the skills on the task analysis. In addition, this study increased efficiency by adding nontargeted information on core content to functional instruction for students with ID. In this study, students increased the amount of nontargeted content information on photosynthesis that they acquired when it was embedded in instruction in a functional skill and maintained this, which increased the efficiency of instruction. Because they acquired some of the embedded core content during instruction on plant care, this decreased the amount of time it took to learn the remaining core content (i.e., 3 days of direct instruction) following exposure to it during the intervention, which is consistent with previous research (Wolery et al., 2000). Specifically, this investigation extends the research to adding core content (i.e., photosynthesis) to functional instruction on a potential employment task (i.e., plant care) that takes place in an employment setting (i.e., greenhouse).
Limitations and Suggestions for Future Research
One limitation to the current investigation was the lack of generalization data collected. Future research could examine programming for generalization by having the classroom teacher deliver the intervention and conducting generalization probes across additional people when students work with job supervisors or even co-workers at the job site. In addition, core content could be generalized to class assessments. Generalization also could be facilitated by teaching across different types of plants. Future researchers could use this as a way to teach multiple exemplars of plants, such as succulents and cacti or flowering and non-flowering.
Another limitation to this study is that, although it was conducted in a greenhouse, the researchers did not conduct it at a specific community employment site. In future studies, researchers could implement the intervention to an actual employment site (e.g., commercial greenhouse, florist shop) away from the high school campus where students might find future employment.
A third limitation is that this study used a single opportunity format; therefore, it is not clear how many steps the students could have completed given the opportunity. The reason the researchers selected this format was to decrease the probability of students learning during baseline condition as well as to decrease the testing fatigue from being asked to perform a task they did not know how to do. This is consistent with other studies (e.g., Britton, Collins, Ault, & Bausch, 2015).
Finally, social validity collected in this study only measured student perceptions. Future studies should consider measuring other aspects of social validity, such as teacher preference for the procedure and whether others value the knowledge and skill students have acquired.
Implications for Practice
Collins et al. (2010) discussed six guidelines for developing instruction on academic standards with meaningful application of content. These guidelines included (a) developing the instructional objective, (b) identifying the context of instruction, (c) selecting an evidence-based instructional strategy, (d) identifying nontargeted information to be added, (e) designing a data collection system, and (f) planning for maintenance and generalization. In the modern era of teaching, time has become more limited and the expectations for teachers more demanding. These guidelines provide teachers and other practitioners with a model and template they can use to plan lessons and incorporate academic content with teaching functional skills.
One way to encourage general education collaboration could be through general education teachers working with career and technical education (CTE) teachers to combine functional skills and academic content. General education teachers could learn how to implement systematic instruction strategies and potentially train students without disabilities to implement these strategies as they work alongside students with disabilities in vocational education training settings (e.g., athletics, culinary arts).
In addition, teachers can incorporate academic content into an employment skill a student is learning. For example, a teacher could take content a student is learning in the classroom and tie it to what the student is doing at his or her employment site. A job coach or peer could be trained to present nontargeted academic information at the job site while a student completes a job task. As demonstrated in Fetko et al. (2013), the nontargeted information does not have to be related to the task the student is performing for the student to learn it.
Conclusion
Studies have demonstrated teachers can use systematic instruction to teach both academic and functional skills. By incorporating the two content areas into the same lesson plan, teachers can make core content more relevant to students’ lives outside of school, as well as conserve time by teaching both concepts at once.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
