1. Response to Intervention: Accelerating Achievement for ALL Students Illinois IEA Professional Development Workshop Dr. George M. Batsche Professor and Co-Director Institute for School Reform Florida Statewide Problem-Solving/RtI Project University of South Florida

2. National Resources to Support District and School Implementation www.nasdse.org –Building and District Implementation Blueprints –Current research (evidence-based practices) that supports use of RtI www.rtinetwork.org –Blueprints to support implementation –Monthly RtI Talks –Virtual visits to schools implementing RtI –Webinars –Progress Monitoring Tools to Assess Level of Implementation www.justreadflorida.org/readingwalkthrough/www.justreadflorida.org –Principal Walk Through Integrity Evaluations www.floridarti.usf.edu –Introductory Course

3. The Vision 95% of students at “proficient” level Students possess social and emotional behaviors that support “active” learning A “unified” system of educational services –One “ED” Student Support Services perceived as a necessary component for successful schooling

4. The Outcomes Maximize effect of core instruction for all students Targeted instruction and interventions for at-risk learners Significant improvements in pro-social behaviors Reduction in over-representation of diverse student groups in low academic performance, special education, suspension/expulsion, and alternative education. Overall improvement in achievement rates Maximize efficiency and return on investment AYP

5. The Model

6. Response to Intervention RtI is the practice of (1) providing high-quality instruction/intervention matched to student needs and (2) using learning rate over time and level of performance to (3) make important educational decisions. (Batsche, et al., 2005) Problem-solving is the process that is used to develop effective instruction/interventions.

7. Problem Solving Process Evaluate Response to Intervention (RtI) Evaluate Response to Intervention (RtI) Problem Analysis Validating Problem Ident Variables that Contribute to Problem Develop Plan Problem Analysis Validating Problem Ident Variables that Contribute to Problem Develop Plan Define the Problem Defining Problem/Directly Measuring Behavior Define the Problem Defining Problem/Directly Measuring Behavior Implement Plan Implement As Intended Progress Monitor Modify as Necessary Implement Plan Implement As Intended Progress Monitor Modify as Necessary

8. Three-Tiered Model of School Supports & the Problem-solving Process ACADEMIC SYSTEMS Tier 3: Comprehensive & Intensive Students who need individualized interventions. Tier 2: Strategic Interventions Students who need more support in addition to the core curriculum. Tier 1: Core Curriculum All students, including students who require curricular enhancements for acceleration. BEHAVIOR SYSTEMS Tier 3: Intensive Interventions Students who need individualized intervention. Tier 2: Targeted Group Interventions Students who need more support in addition to school-wide positive behavior program. Tier 1: Universal Interventions All students in all settings.

9. Model of Schooling All district instruction and intervention services have a “place” in this model. If it does not fit in the model, should it be funded? All supplemental and intensive services must be integrated with core.

10. Problem-Solving/RtI Resource Management Public Education Resource Deployment –Support staff cannot resource more than 20% of the students –Service vs Effectiveness-- BIG ISSUE 1-5% 5-10% 80-90% Students AcademicBehavior

11. RtI: Framing Issues and Key Concepts Academic Engaged Time (AET) is the best predictor of student achievement –330 minutes in a day, 1650 in a week and 56,700 in a year –This is the “currency” of instruction/intervention –Its what we have to spend on students –How we use it determines student outcomes. MOST students who are behind will respond positively to additional CORE instruction. –Schools have more staff qualified to deliver core instruction than specialized instruction. –Issue is how to schedule in such a way as to provide more exposure to core.

12. RtI: Framing Issues and Key Concepts Managing the GAP between student current level of performance and expectation (benchmark, standards, goal) is what RtI is all about. The two critical pieces of information we need about students are: –How BIG is the GAP? »AND –How much time do we have to close it? The answers to these 2 questions defines our instructional mission.

13. RtI: RATE Rate is growth per week (month) necessary to close the GAP Rate becomes the statistic we need to define evidence-based intervention (EBI) EBI is any intervention that results in the desired RATE

14. RtI: 3 Priorities 1. Prevention: Identify students at-risk for literacy failure BEFORE they actually fail. –Kindergarten screening, intervention and progress monitoring is key. –No excuse for not identifying ALL at-risk students by November of the kindergarten year. –This strategy prevents the GAP. –Managing GAPs is more expensive and less likely to be successful.

15. RtI: 3 Priorities 2.Early Intervention –Purpose here is the manage the GAP. –Students who are more that 2 years behind have a 10% chance, or less, or catching up. –Benchmark, progress monitoring data, district-wide assessments are used to identify students that have a gap of 2 years or less. –Students bumping up against the 2 year level receive the most intensive services. –This more costly and requires more specialized instruction/personnel

16. RtI: 3 Priorities 3.Intensive Intervention –Reserved for those students who have a GAP of more than 2 years and the rate of growth to close the GAP is unrealistic. Too much growth—too little time remaining. –Problem-solving is used to develop instructional priorities. –This is truly a case of “you cannot do something different the same way.” –This is the most costly, staff intensive and least likely to result in goal attainment

17. How Does it Fit Together? Standard Treatment Protocol Addl. Diagnostic Assessment Instruction Results Monitoring Individual Diagnostic Individualized Intensive weekly All Students at a grade level ODRs Monthly Bx Screening Bench- Mark Assessment Annual Testing Behavior Academics None Continue With Core Instruction Grades Classroom Assessments Yearly Assessments Standard Protocol Small Group Differen- tiated By Skill 2 times/month Step 1 Step 2Step 3Step 4 Supplemental 1-5% 5-10% 80-90% Core Intensive

18. Critical Components Data are used to evaluate the effectiveness of core instruction –80% of students receiving ONLY core instruction are proficient Supplemental Instruction/Intervention uses a “standard protocol” of instruction based on student needs, informed by data –70% of students receiving Supplemental AND Core are proficient

19. Critical Components Intensive instruction developed for students who have not responded as desired to Core PLUS Supplemental Instruction

20. What Does the Research Say About RtI?

21. Effective Schools 30% or more of students at risk but who were at grade level at the end of the year. Characteristics –Strong Leadership –Positive Belief and Teacher Dedication –Data Utilization and Analysis –Effective Scheduling –Professional Development –Scientifically-Based Intervention Programs –Parent Involvement »(Crawford and Torgeson) » (

22. Data on the Top 10 Schools Meeting the Effective School Criteria SchoolEI score EI %ile ECI score ECI %ile % free & reduced lunch % minority % ELL# of children in K-3 A39998382898447499 B36978379999855463 C34958995808322455 D33938893 9442487 E339184 757831428 F32898589858037618 G3289806793 25480 H328984 736731556 I31897966879527301 J31898067709911575

23. What is the impact of PSM/RtI on students from diverse backgrounds? VanDerHeyden, et al. report that students responded positively to the method and that African-American students responded more quickly than other ethnic groups. Marston reported a 50%decrease in EMH placements over a 6-year period of time. Marston reported a drop over a 3-year period in the percent of African- American students placed in special education from 67% to 55%, considering 45% of the student population was comprised of African- American Students. Batsche (2006) reported a significant decrease in the risk indices for ELL and African-American students

24. Risk Indices by Year & Race/Ethnicity

25. Response to Intervention Implementation

26. How Do We “Do” RtI? Organized by a District PLAN Driven by Professional Development Supported by Coaching and Technical Assistance Informed by DATA

27. Change Model Consensus Infrastructure Implementation

28. Stages of Implementing Problem-Solving/RtI Consensus –Belief is shared –Vision is agreed upon –Implementation requirements understood Infrastructure Development –Problem-Solving Process –Data System –Policies/Procedures –Training –Tier I and II intervention systems E.g., K-3 Academic Support Plan –Technology support –Decision-making criteria established Implementation

29. Building Consensus Knowledge Beliefs Understanding the “Need”- DATA Skills and/or Support

30. Consensus: Essential Beliefs No child should be left behind It is OK to provide differential service across students Academic Engaged Time must be considered first Student performance is influenced most by the quality of the interventions we deliver and how well we deliver them- not preconceived notions about child characteristics Decisions are best made with data Our expectations for student performance should be dependent on a student’s response to intervention, not on the basis of a “score” that “predicts” what they are “capable” of doing.

31. Consensus Development: Data Are you happy with your data? Building/Grade Level Student Outcomes –Disaggregated –AYP

33. Knowledge and Skill Requirements

34. Personnel Critical to Successful Implementation District-Level Leaders Building Leaders Facilitator Teachers/Student Services Parents Students

35. Development of the Infrastructure

36. Key Points Unit of implementation is the building level. Implementation process takes 4-6 years. Implementation progress must be monitored Must be guided by data indicating implementation level and integrity Must be supported by professional development and technical assistance Drive by a strategic plan It is a journey, not a sprint

37. Implementation Model District-based leadership team (DBLT) School-based leadership team (SBLT) School-based coach –Process Technical Assistance –Interpretation and Use of Data Evaluation Data

38. The Infrastructure

39. Problem Solving Process Evaluate Response to Intervention (RtI) Evaluate Response to Intervention (RtI) Problem Analysis Validating Problem Ident Variables that Contribute to Problem Develop Plan Problem Analysis Validating Problem Ident Variables that Contribute to Problem Develop Plan Define the Problem Defining Problem/Directly Measuring Behavior Define the Problem Defining Problem/Directly Measuring Behavior Implement Plan Implement As Intended Progress Monitor Modify as Necessary Implement Plan Implement As Intended Progress Monitor Modify as Necessary

40. Steps in the Problem-Solving Process 1.PROBLEM IDENTIFICATION Identify replacement behavior Data- current level of performance Data- benchmark level(s) Data- peer performance Data- GAP analysis 2.PROBLEM ANALYSIS Develop hypotheses( brainstorming) Develop predictions/assessment 3.INTERVENTION DEVELOPMENT Develop interventions in those areas for which data are available and hypotheses verified Proximal/Distal Implementation support 4.Response to Intervention (RtI) Frequently collected data Type of Response- good, questionable, poor

41. Data For Each Tier - Where Do They Come From? Tier 1: Universal Screening, accountability assessments, grades, classroom assessments, referral patterns, discipline referrals Tier 2: Universal Screening - Group Level Diagnostics (maybe), systematic progress monitoring, large-scale assessment data and classroom assessment Tier 3: Universal Screenings, Individual Diagnostics, intensive and systematic progress monitoring, formative assessment, other informal assessments

42. “Academic” Behaviors Class work completed/accuracy Home work completed/accuracy Test scores/accuracy Student Level of Performance Goal or benchmark Peer level of performance

43. Example Data taken during a single grading period (6 weeks) Progress Monitor Homework completed and accuracy –Goal: Completed 75%, Accuracy 75% –Student: Completed 40%, Accuracy 50% –Peers: Completed 65%, Accuracy 78% –Time Frame: 6 weeks –Assignments/Week: 20

44. Example Completion: 75-40=30 % improvement in 6 weeks 30%/6 weeks= Improvement rate of 5%/week 5% of 20 assignments=1 per week Rate of Improvement for an effective intervention is 1 ADDITIONAL ASSIGNMENT PER WEEK

45. Decision Rules: What Constitutes “Good” RtI?

46. Decision Rules Response to Intervention Rules Linking RtI to Intervention Decisions

47. Decision Rules: What is a “Good” Response to Intervention? Positive Response –Gap is closing –Can extrapolate point at which target student(s) will “come in range” of target--even if this is long range –Level of “risk” lowers over time Questionable Response –Rate at which gap is widening slows considerably, but gap is still widening –Gap stops widening but closure does not occur Poor Response –Gap continues to widen with no change in rate.

48. Performance Time Positive Response to Intervention Expected Trajectory Observed Trajectory

49. Decision Rules: What is a “Questionable” Response to Intervention? Positive Response –Gap is closing –Can extrapolate point at which target student(s) will “come in range” of target--even if this is long range Questionable Response –Rate at which gap is widening slows considerably, but gap is still widening –Gap stops widening but closure does not occur –Level of “risk” remains the same over time Poor Response –Gap continues to widen with no change in rate.

50. Performance Time Questionable Response to Intervention Expected Trajectory Observed Trajectory

51. Decision Rules: What is a “Poor” Response to Intervention? Positive Response –Gap is closing –Can extrapolate point at which target student(s) will “come in range” of target--even if this is long range Questionable Response –Rate at which gap is widening slows considerably, but gap is still widening –Gap stops widening but closure does not occur Poor Response –Gap continues to widen with no change in rate. –Level of “risk” worsens over time

52. Performance Time Poor Response to Intervention Expected Trajectory Observed Trajectory

53. Performance Time Response to Intervention Expected Trajectory Observed Trajectory Positive Questionable Poor

54. Decision Rules: Linking RtI to Intervention Decisions Positive Continue intervention with current goal Continue intervention with goal increased Fade intervention to determine if student(s) have acquired functional independence.

55. Decision Rules: Linking RtI to Intervention Decisions Questionable –Was intervention implemented as intended? If no - employ strategies to increase implementation integrity If yes - –Increase intensity of current intervention for a short period of time and assess impact. If rate improves, continue. If rate does not improve, return to problem solving.

56. Decision Rules: Linking RtI to Intervention Decisions Poor –Was intervention implemented as intended? If no - employ strategies in increase implementation integrity If yes - –Is intervention aligned with the verified hypothesis? (Intervention Design) –Are there other hypotheses to consider? (Problem Analysis) –Was the problem identified correctly? (Problem Identification)

57. BUILDING THE FOUNDATION

58. 10 - 15% Tier I Problem-Solving: Data and Skills Needed 80 - 90% Tier I - Assessment Discipline Data (ODR) Benchmark Assessment School Climate Surveys Universal Screening FCAT Universal Screening District-Wide Assessments Tier I - Core Interventions School-wide Discipline Positive Behavior Supports Whole-class Interventions Core Instruction

60. H

61. Tier 1 Data Example

62. Referral Analysis 42% Noncompliance 30% Off-Task/Inattention 12% Physical/Verbal Aggression 6% Relational Aggression 10% Bullying

63. Building-Level Behavior Data % Building %Referred Male 50%80% White 72%54% Hispanic 12%20% African American 15% 24% Other 1% 2% Low SES 25%50%

64. What does core instruction look like for reading? K-5 –90 minute reading block Comprehensive reading program is the central tool for instruction. Explicit, systematic, and differentiated instruction is provided. In-class grouping strategies are in use, including small group instruction as appropriate to meet student needs. Active student engagement occurs in a variety of reading-based activities, which connect to the essential components of reading and academic goals. Effective classroom management and high levels of time on task are evident. 6-12 –Content area courses in which the reading content standards are addressed for all students including: Middle School Developmental Reading English/Language Arts Other core areas such as science, social studies, and math

65. What strategies exist to differentiate instruction for K-5 students in Tier 1? Differentiate in small, flexible reading groups –Use data to form groups based on skills to be taught (comprehension, phonics, etc.) –Ensure that groups are flexible –Determine a schedule to rotate children through groups/centers –Ensure that students with the most intensive needs meet in the teacher-led center everyday Targeted and deliberate independent reading practice that utilizes relevant practice, extension, and production opportunities

66. What strategies exist to differentiate instruction for 6-12 students in Tier 1? CAR-PD Differentiate in small groups –Use data to from groups based on skills to be taught –Groups need to be flexible –Determine a schedule to rotate students through groups Support from the reading coach Take responsibility for student learning

67. What data can be collected to evaluate the impact of core instruction? Progress monitoring assessments three times a year (Benchmarking) Ongoing Progress Monitoring (OPM) Core Reading Program Unit Tests / Curriculum- based assessments Outcome measures (SAT-10 and State Tests) to make decisions about student placement for the following year

68. What strategies are available to evaluate the fidelity of core instruction? Principal Reading Walk Through –“If it gets inspected, it gets respected” Effective instruction checklist Elementary core reading program checklists

69. Effective Instruction (Foorman et al., 2003; Foorman & Torgesen, 2001; Arrasmith, 2003; & Rosenshine, 1986) CharacteristicGuiding QuestionsWell MetSomewhat Met Not Met Goals and ObjectivesAre the purpose and outcomes of instruction clearly evident in the lesson plans? Does the student understand the purpose for learning the skills and strategies taught?   ExplicitAre directions clear, straightforward, unequivocal, without vagueness, need for implication, or ambiguity?  SystematicAre skills introduced in a specific and logical order, easier to more complex? Do the lesson activities support the sequence of instruction? Is there frequent and cumulative review?  ScaffoldingIs there explicit use of prompts, cues, examples and encouragements to support the student? Are skills broken down into manageable steps when necessary?  Corrective FeedbackDoes the teacher provide students with corrective instruction offered during instruction and practice as necessary?  ModelingAre the skills and strategies included in instruction clearly demonstrated for the student?  Guided PracticeDo students have sufficient opportunities to practice new skills and strategies with teacher present to provide support?  Independent ApplicationDo students have sufficient opportunities to practice new skills independently? PacingIs the teacher familiar enough with the lesson to present it in an engaging manner? Does the pace allow for frequent student response? Does the pace maximize instructional time, leaving no down-time?  Instructional RoutineAre the instructional formats consistent from lesson to lesson? 

70. 80 - 90% 10 - 15% 1 - 5% Tier II Problem-Solving Data and Skills Needed Tier II - Targeted Interventions Targeted Group Interventions Increased Intensity Narrow Focus Linked to Tier I 80 - 90% 10-15% Tier II - Assessment Behavioral Observations Intervention Data Group Diagnostic Universal Screening Progress Monitoring Tier I - Core InterventionsTier I Assessment

71. Data Infrastructure: Using Existing Data to Predict Intervention Needs for Tier 2 Previous referral history predicts future referral history Benchmark and Progress Monitoring Data Common Assessments in Middle and High School Middle and High School –Student data history prior to entering

72. Data-Driven Infrastructure: Establishing a Building Baseline Code referrals (reasons) for past 2-3 years –Identifies problems teachers feel they do not have the skills/support to handle –Referral pattern reflects skill pattern of the staff, the resources currently in place and the “history” of what constitutes a referral in that building –Identifies likely referral types for next 2 years –Identifies focus of Professional Development Activities AND potential Tier II and III interventions –Present data to staff. Reinforces “Need” concept

73. Tier Functions/Integration How the Tiers work Time aggregation Tier integration

74. How the Tiers Work Goal: Student is successful with Tier 1 level of support-academic or behavioral Greater the tier, greater support and “severity” Increase level of support (Tier level) until you identify an intervention that results in a positive response to intervention Continue until student strengthens response significantly Systematically reduce support (Lower Tier Level) Determine the relationship between sustained growth and sustained support.

75. Integrating the Tiers 5th grade student reading at the 2nd grade level –Tier 3 Direct Instruction, Targeted, Narrow Focus (e.g., phonemic awareness, phonics, some fluency) –Tier 2 Fluency, vocabulary, comprehension, pre-teach for Tier 1 –Tier 1 Focus on comprehension, participation, scripted decoding Use core materials for content Progress monitor both instructional level and grade placement level skills

76. What do we know about the characteristics of effective interventions? They always increase the intensity of instruction - they accelerate learning They always provide many more opportunities for re-teaching, review, and practice They are focused carefully on the most essential learning needs of the students.

77. Characteristics of Tier 2 Interventions Available in general education settings Opportunity to increase exposure (academic engaged time) to curriculum Opportunity to narrow focus of the curriculum Sufficient time for interventions to have an effect (10-30 weeks) Often are “standardized” supplemental curriculum protocols

78. Interventions: Tier 2 First resource is TIME (AET) –HOW much more time is needed? Second resource is curriculum –WHAT does the student need? Third resource is personnel –WHO or WHERE will it be provided?

79. Tier 2: Getting TIME “Free” time--does not require additional personnel –Staggering instruction –Differentiating instruction –Cross grade instruction –Skill-based instruction Standard Protocol Grouping Reduced range of “standard” curriculum After-School Home-Based

80. Tier 2: Curriculum Standard protocol approach Focus on essential skills Most likely, more EXPOSURE and more FOCUS of core instruction Linked directly to core instruction materials and benchmarks Criterion for effectiveness is 70% of students receiving Tier 2 will reach benchmarks

81. Tier 2: Personnel EVERYONE in the building is a potential resource Re-conceptualize who does what Personnel deployed AFTER needs are identified WHERE matters less and less REMEMBER, student performance matters more than labels, locations and staff needs. A school cannot deliver intensive services to more than 7% of the population

82. 3 Fs + 1 S + Data + PD = Effective & Powerful Instruction Frequency and duration of meeting in small groups – every day, etc. Focus of instruction (the What) – work in vocabulary, phonics, comprehension, etc. Format of lesson (the How) – determining the lesson structure and the level of scaffolding, modeling, explicitness, etc. Size of instructional group – 3, 6, or 8 students, etc. Use data to help determine the 3 Fs and 1 S (the Why) Provide professional development in the use of data and in the 3 Fs and 1 S

83. What does supplemental instruction/intervention look like for reading? Logistics of supplemental instruction/ intervention –Specific time and place included in schedule –Who will provide it? (classroom teacher or outside support – Reading specialist, ESE, SLP, etc.) –Materials/how will the provider access them? –Common planning time established between the classroom teacher and intervention teacher, if applicable –Establish guidelines for when to evaluate the effectiveness of instruction and guidelines to determine what is a “good” response

84. Intervention Support Intervention plans should be developed based on student need and skills of staff All intervention plans should have intervention support Principals should ensure that intervention plans have intervention support Teachers should not be expected to implement plans for which there is no support

85. Critical Components of Intervention Support Support for Intervention Integrity Documentation of Intervention Implementation Intervention and Eligibility decisions and outcomes cannot be supported in an RtI model without these two critical components

86. Intervention Support Pre-meeting –Review data –Review steps to intervention –Determine logistics First 2 weeks –2-3 meetings/week –Review data –Review steps to intervention –Revise, if necessary

87. Intervention Support Second Two Weeks –Meet twice each week Following weeks –Meet at least weekly –Review data –Review steps –Discuss Revisions Approaching benchmark –Review data –Schedule for intervention fading –Review data

91. Tier 3 Decisions GAP? Rate?? Independent Functioning? –Fade Intervention to Supplemental Level –Evaluate Rate

92. Tier 3 Individual and Very Small Group Individual Diagnostic Procedures Intensive Interventions Goal is to determine interventions that close the GAP Pre-requisite for consideration for any special education program

93. Ways that instruction must be made more powerful for students “at-risk” for reading difficulties. More instructional time More powerful instruction involves: Smaller instructional groups Clearer and more detailed explanations More systematic instructional sequences More extensive opportunities for guided practice More opportunities for error correction and feedback More precisely targeted at right level resources skill

94. What are the logistics of Tier 3 instruction? –Specific place and time set aside on the schedule (daily) –Who will provide it? (classroom teacher or outside support – Reading specialist, ESE, SLP, etc.) –Materials/how will the provider access them? –Common planning time established between the two providers, if applicable –Establishing guidelines for when to evaluate the effectiveness of instruction and guidelines to determine what is a “good” response

95. Ongoing Progress Monitoring (OPM) K-2 –all of the same TDI tasks – ORF in grades 1 and 2 3-12 –ORF at grades 3-5 –MAZE at grades K-12 –Informal toolkit with: Instructional Level reading comprehension passages & passage-specific Question & Response templates Multiple Lexiled passages for oral reading fluency, accuracy, and comprehension Phonics Inventory Sight Word Inventory Instructional Implications of Word Analysis Task

96. How do we ensure that Tier 3 instruction is integrated with/includes core instructional content when appropriate and transfers to student success in core? Instructors need to communicate, if applicable Both instructors must have access to the core materials, if applicable Understanding the core content in order to provide access to the information but at an appropriate reading level

97. Data-Based Determination of Expectations: Elsie Benchmark Level:100 WCPM Current Level:47 WCPM Difference to June Benchmark (Gap):53 WCPM Time to Benchmark: 41 Weeks Rate of Growth Required: –53/41= 1.29 WCPM for Elsie Peer Group Rate = about 1.1 WCPM growth (at benchmark) 1.2 WCMP (for “some risk” benchmark) REALISTIC? Not unless you increase AET

98. Questionable RtI

99. Tier 2- Supplemental Instruction - Revision The intervention appeared to be working. What the teachers thought was needed was increased time in supplemental instruction. They worked together and found a way to give Elsie 30 minutes of supplemental instruction, on phonics and fluency, 5x per week.

100. Data-Based Determination of Expectations: Elsie Benchmark Level:100 WCPM Current Level:56 WCPM Difference to June Benchmark (Gap):44 WCPM Time to Benchmark: 27 Weeks Rate of Growth Required: –44/27= 1.62 WCPM for Elsie Peer Group Rate = 1.1 WCPM growth (at benchmark) 1.2 WCMP (for “some risk” benchmark) REALISTIC? Not unless you increase AET

102. Good RtI

103. Aimline= 2 percent/week Trendline = 3 percent/week

104. Aimline= 1.50 words/week Trendline = 0.95 words/week

105. Behavioral Case Examples

106. II