Ontario's daily physical activity policy for elementary schools: is everything in place for success?

Robertson-Wilson, Jennifer E. ; Levesque, Lucie

Overweight and obesity rates among Canadian youth have increased over the last three decades. (1,2) Recent data suggest that over one quarter of Canadian youth can be classified as overweight or obese. (1) The association between youth physical activity and weight status has been established. (3-5) A recent review (6) acknowledges the role of physical activity in promoting other outcomes such as improvements to skeletal health, academic outcomes, and anxiety reduction. Data show, however, that fewer than 10% of Canadian youth meet Canada's physical activity guidelines based on the number of steps taken. (7)

The role of policy in the promotion of health behaviours is recognized in several forms including the Ottawa Charter for Health Promotion (8) and social-ecological models. (9-11) Brownson and colleagues (12) note that policy and environment interventions move beyond individually-targeted interventions to effect possible change within the larger population. Given the need for physical activity policy research, (12,13) Brownson et al.'s (12) study using concept mapping with researchers and practitioners identifies school physical activity policy as an important research area. Also highlighted is the need to evaluate existing policies. (12) Public health is listed as one of many possible research partners to advance this agenda. (12) In Ontario, public health has a mandate to promote physical activity in schools (14) with recent guidelines to "influence the development and implementation of healthy policies ..." (p. 19) related to physical activity and other issues within schools. (15)

In response to concerns of inactivity, the Ontario Ministry of Education (OME) recently mandated Memorandum No. 138 whereby "school boards must ensure that all elementary students, ..., have a minimum of twenty minutes of sustained moderate to vigorous physical activity each school day during instructional time" (para 4). (16) In addition to policy development, policy implementation and evaluation are important stages in the policy process. (13,17-19) Policy "implementation represents the conscious conversion of policy plans into reality" (p. 94), (19) while "policy evaluation assesses the effectiveness of a public policy ..." (p.119). (19) Identifying implementation challenges during policy development and examining policy implementation are important given policy effectiveness may be determined by implementation. (17,19) Given that this is relevant for school-related physical activity policy, (20) the purpose of the present analysis is to examine the new DPA policy for Ontario elementary schools.

As a beginning step, evidence of implementation strategies contained within the OME policy documents can be examined. Several authors highlight policy features thought to facilitate (put not predict in absolute terms) implementation. (17,19) Hogwood and Gunn provide a framework of 10 preconditions (see Table 1) considered important for "perfect implementation" (p. 198). (17) They acknowledge that while perfect implementation may be unrealistic and nonprescriptive, (17,21) policy implementation is likely to be fur ther challenged when these preconditions are not considered. (21) Hogwood and Gunn's preconditions may be considered useful when viewed as suggestions for those developing policies. (22)

We used Hogwood and Gunn's framework (17) as a lens to examine publicly-available OME documents for implementation strategies related to Memorandum No. 138. Challenges to DPA policy implementation will be discussed along with next steps for DPA policy implementation and evaluation in Ontario.

METHODS

The DPA policy document, (16) official Memoranda to board directors and principals (23,24) and other OME documents (25-31) related to DPA implementation strategies were collected from the OME's and related websites between October 2005 and October 2007. Additional information from the Ontario Physical and Health Education Association (OPHEA) (32,33) (a partner in the development of several implementation strategies) was also used. The first author, who has expertise in school-based physical activity, read and compared the above documents regarding DPA policy implementation against each of the 10 preconditions (17) in order to assess the evidence for the precondition as an implementation strategy. The authors then used investigator triangulation to corroborate the assessment.

RESULTS

Precondition 1

The DPA implementing agencies are schools and boards. From the policy documents reviewed, (16,23,24) the policy is not subject to veto from other government agencies. (17) The policy is "effective: until revoked or modified" (16) meaning the only political constraint (17) may be the degree to which the DPA policy will be supported and sustained by future Ontario governments. Potential external crippling physical constraints (17) (e.g., weather, collective agreement provisions affecting staff deployment) are not explicitly mentioned.

Precondition 2 and 3

School boards were expected to implement Memorandum No. 138 "as soon as possible" after the policy was announced on October 6, 2005 with full implementation "by the end of the 2005-06 school year" (para 8). (16) To facilitate the implementation of DPA during instructional time, strategies provided by the OME in the policy document include providing DPA during regular physical education class or integrating DPA in other curricular areas. (16,23,24) The OME promised several million dollars for DPA implementation resources and training. (25) Additional funding was announced for the subsequent school year. (33) Resource guides for teachers (26-28) and guides (with implementation strategies) for school boards29 and principals, (30) and an online training resource31 were created by the OME and partners. (23,24) Thus, both the timeline and provision of resources was considered by the OME.

Whether the above resources and timeline are "sufficient" and were made "available at the right time in the process" (p. 173) (21) is less clear. Memorandum 138 was publicly enacted on October 6, 2005, (16) yet resources were made available at different points. Sample resource guides were available prior to the actual release of the guides in March 2006 (23,24,32) in advance of end of 2005-06 year. However, board and principal guides were not yet available for release in March 2006. (32) Professional development was not available before the policy was mandated. OPHEA's initial update cited DPA-related training as one item needed to support DPA implementation. (32) Although school boards received DPA funding from the OME in December 2005, they were given one month's notice in March 2006 to finish spending the funds. (32) While additional funding was provided in 2006-07, (33) a long-term funding strategy to sustain the resources and training required for continued DPA implementation is not apparent. A lack of material resources, facilities, equipment, and qualified personnel has been shown to hinder teachers' abilities to implement physical education curricula (34-38) and may also be important for DPA implementation. A recent report, (39) cited in Active Healthy Kids Canada's report card, (40) suggests that implementation challenges for DPA thus far include scheduling, materials, space, and professional development. (39) Thus, DPA implementation resources may not be sufficient or sustainable.

Precondition 4 and 5

According to Hogwood and Gunn, utilizing cause-effect theory in policy implementation is critical in order to determine whether poor policy outcomes result from poor implementation or from inappropriate theory concerning how the policy is hypothesized to work. (17,21) The causal chain for the DPA policy is suggested by the OME: "The goal of [DPA] is to enable all elementary students to improve or maintain their physical fitness and their overall health and wellness, and to enhance their learning opportunities" (para 4). (16) While there is some support for this goal given associations between physical activity and health and learning outcomes, (3-6) what is less clear is whether the stipulated 20 minutes is sufficient to attain these objectives. Janssen's review of Canadian physical activity guidelines for children and youth suggests that additional dose-response evidence is needed to better inform physical activity recommendations. (41) Current Canadian guidelines advocate for children and youth to increase their moderate-vigorous physical activity over several months to attain 90 minutes a day. (42,43) Given current physical activity levels, (7) 20 minutes of DPA may provide one way to begin to increase student physical activity levels, but may be insufficient for students to attain current Canadian recommendation. For precondition 5, the causal chain can be argued to be direct (17,21) as DPA is believed to impact health and learning outcomes. Future assessment of student outcomes will confirm this.

Precondition 6

For this precondition, Hogwood and Gunn recommend that "there is a single implementing agency which need not depend on other agencies for success, or if other agencies must be involved, that the dependency relationships are minimal in number and importance" (p. 202). (17) School and board success may depend on other support agencies to provide resources and knowledge. OPHEA was involved in facilitating DPA implementation by working with the OME to provide teacher resource guides and also by providing other free and fee-based resources and training services. (23,24,32,33) Another OME suggestion is to provide "formal opportunities for teachers to" network among themselves to foster DPA implementation ideas (para 10). (23,24) Further, "Schools are encouraged to invite parents and community organizations to support the implementation of [DPA] ..." (para 10). (23) Public health is one such organization mentioned in the principal and school board guides. (29,30) With their mandate to promote health in schools, (14,15) public health units are a natural partner to assist in DPA implementation. Thus, contrary to the recommended precondition, the DPA implementing agencies (i.e., schools and school boards) rely on numerous partners to facilitate DPA implementation.

Precondition 7

In terms of understanding the objectives, (17) the expectations of Memorandum No. 138 are clearly articulated in the policy (16,23,24) and resource (26-30) documents for broad understanding by key stakeholders including teachers, schools, and boards as requiring "twenty minutes of sustained moderate to vigorous physical activity each school day during instructional time" (para 4). (16) Moderate and vigorous physical activity are also defined in the resource guides. (26-30) Yet, it is not possible to gauge the degree to which these stakeholders agree with these objectives from available policy-related documents. Further investigation (e.g., stakeholder interviews) is required to learn how teachers view the place of DPA (44) for increasing youth physical activity, especially as it relates to suggested physical education curricula. (45)

Precondition 8

Hogwood and Gunn suggest that the role of each stakeholder/person involved in the implementation process should be made explicit. (17) The memo to Directors of Education suggests that "at the local level it will be important for boards, principals, and teachers to begin discussions on methods of effective implementation of the daily physical activity requirement" (para 10). (23) Schools will undoubtedly require different implementation strategies based on school-specific contexts, needs, and resources that are likely to facilitate DPA implementation. Consistent with precondition 8, policysupporting materials (i.e., DPA principal and school board resource guides (29,30)) outline the general responsibilities of multiple partners in DPA implementation, namely the students, teachers, principals, boards, parents, and community and provide suggestions of steps to consider when implementing DPA.

Precondition 9 and 10

In their presentation of precondition 9, Hogwood and Gunn argue that communication channels are rarely smooth in the real world and that with any policy implementation it is difficult to "ensure that ... data, advice, and instructions are understood as intended by the senders, or indeed, understood at all" (p. 205). (17) With DPA, the flow of communication from the OME to school boards, to schools, and to teachers provides several avenues where DPA communication or coordination may break down or be inadequate. An example of the latter point may be the one month timeline given for boards to use unspent DPA funds in March of 2006. (32)

The interpretation of precondition 10 is that absolute compliance to the policy can be demanded without opposition. (17,21) Under real world conditions, this is unlikely to be attained and reasons for noncompliance can inform the policy process. (17) In theory, compliance is expected of teachers, principals, and boards because they are required to follow and implement OME curricula. The OME implementation strategy gives school boards the task of monitoring DPA implementation. (16) If implementation of school physical activity policy is not evaluated, outcomes cannot be assessed and interpreted nor can possible areas for improvement to implementation be identified. (20) While it is encouraging that the OME had solicited proposals to examine implementation of DPA (33) and OPHEA also recognizes the need for DPA evaluation, (32) no public information concerning this evaluation is currently available from the OME's DPA website (as of July 2008; see also Ramanathan et al. (46) for a discussion of DPA evaluation). Alberta (which implemented a 30-minute DPA policy around the same time as Ontario) has produced a report examining DPA implementation that is available on the Alberta Education website. (47) To our knowledge, the only public DPA implementation evaluation information in Ontario comes from People for Education. (39) In addition to the barriers previously mentioned, they reported that 98% of school principals self-reported that DPA was being implemented. (39) Additional evaluation is needed given the survey was not completed by teachers, the school response rate was low, and it is unclear at what level DPA is being implemented.

Further, in areas such as literacy and numeracy, province-wide student testing allows for evaluation and tracking of student learning achievement. (48) Unlike these more formal, public, and rigorous province-wide evaluations for numeracy and literacy, the OME policy documents (16,23,24) do not specify such evaluation of student outcomes related to DPA. Evaluation of student physical activity, fitness, learning, and health outcomes, which will be needed to assess implications of precondition 4 and 5, has thus far been absent. (44,46)

CONCLUSION

Ontario's new DPA policy represents one recent school-based attempt to increase student physical activity. Given the need to examine other phases of the policy process, (13,17-19) this paper represents a first step in assessing proposed DPA policy implementation strategies using the framework of Hogwood and Gunn. (17) While we acknowledge that this lens represents only one approach to examining DPA strategies outlined within publicly available policy documents, it is nonetheless a useful framework to evaluate optimal DPA implementation. In identifying proposed implementation strategies, this paper also furthers the discussion of DPA evaluation (44,46) to determine the impact of proposed DPA implementation strategies. This paper also supports the position that rigorous and long-term impact evaluation of DPA as an education-based health intervention is needed in order to ascertain the outcomes of this policy. (44,46)

It should be acknowledged that this examination of DPA policy implementation was limited to publicly available documents from the OME and related sites. A review of internal OME documents or memos and interviews with knowledgeable officials at the OME would likely yield additional insight into implementation plans and rationales behind certain features of the developed policy. Thus, while the DPA policy accounts for several factors which will no doubt enhance implementation, filling in gaps in the DPA implementation strategy may be needed to continue to help translate the DPA policy into action within Ontario schools.

A role for public health

With standards that include facilitating policy implementation in schools (p. 19) (15) and as recognized by the OME, (29,30) public health units in Ontario may be a valuable partner for DPA implementation. Public health program evaluation is also suggested. (15) As such, if DPA program-related resources, training, or support are provided to schools through public health efforts, implementation evaluation of the challenges, facilitators, and use of resources could be conducted and publicly shared among public health units and with school stakeholders across the province. This is in accordance with one of OPHEA's implementation and evaluation ideas. (32) This would add to the knowledge base in terms of the role of public health professionals in DPA implementation with a focus on optimal implementation strategies (preconditions). Further, this would foster dialogue and networking across public health units and school boards to consolidate and share resources and expertise (32) given funding uncertainties. Finally, given the requirement of evaluating public health programs, (15) public health professionals could advocate for the same consideration in education when health-related programming is issued.

Received: March 27, 2008

Accepted: November 11, 2008

REFERENCES

(1.) Sheilds M. Measured obesity: Overweight Canadian children and adolescents. Nutrition: Findings from the Canadian Community Health Survey. Statistics Canada Catologue No 82-620-MWE2005001, 2005. Available online at: http://www.statcan.ca/english/research/82-620-MIE/2005001/pdf/cobesity.pdf (Accessed July 30, 2008).

(2.) Tremblay MS, Katzmarzyk PT, Willms JD. Temporal trends in overweight and obesity in Canada. Int J Obes 2002;26:538-43.

(3.) Janssen I, Katzmarzyk PT, Boyce WF, King MA, Pickett W. Overweight and obesity in Canadian adolescents and their association with dietary habits and physical activity patterns. J Adoles Health 2004;35:360-67.

(4.) Janssen I, Katzmarzyk PT, Boyce WF, Vereecken C, Mulvihill C, Currie RC, Pickett W, HBSC Obesity Working Group. Comparison of overweight and obesity prevalence in school-aged youth from 34 countries and their relationships with physical activity and dietary patterns. Obes Rev 2005;6:123-32.

(5.) Tremblay MS, Willms JD. Is the Canadian childhood obesity epidemic related to physical inactivity? Int J Obes 2003;27:1100-5.

(6.) Strong WB, Malina RM, Blimkie CJ, Daniels SR, Dishman RK, Gutin B, et al. Evidence based physical activity for school-age youth. J Pediatr 2005;146:732-37.

(7.) Cameron C, Wolfe R, Craig CL. Physical activity and sport: Encouraging children to be active. Ottawa, ON: Canadian Fitness and Lifestyle Research Institute, 2007. Available online at: http://www.cflri.ca/eng/statistics/surveys/ documents/PAM2005.pdf (Accessed January 2008).

(8.) Canadian Public Health Association. Ottawa Charter for Health Promotion. 1996. Available online at: http://www.phac-aspc.gc.ca/ph-sp/phdd/pdf/ charter.pdf (Accessed August 28, 2005).

(9.) McLeroy KR, Bibeau D, Steckler A, Glanz K. An ecological perspective on health promotion programs. Health Educ Q 1988;15(4):351-77.

(10.) Sallis JF, Owen N. Ecological models. In: Glanz K, Lewis FM, Rimer BK (Eds.), Health Behavior and Health Education: Theory, Research, and Practice, 3rd ed. San Francisco, CA: Jossey-Bass, 2002;462-84.

(11.) Richard L, Potvin L, Kishchuk N, Prlic H, Green LW. Assessment of the integration of the ecological approach in health promotion programs. Am J Health Promot 1996;10(4):318-28.

(12.) Brownson RC, Kelly CM, Eyler AA, Carnoske C, Grost L, Handy SL, et al. Environmental and policy approaches for promoting physical activity in the United States: A research agenda. J Phys Act Health 2008;5:488-50.

(13.) Schmid TL, Pratt M, Witmer L. A framework for physical activity policy research. J Phys Act Health 2006;3(Suppl 1):S20-S29.

(14.) Ministry of Health (Public Health Branch). Mandatory Health Programs and Service Guidelines, 1997. Available online at: http://www.health.gov.on.ca/ english/providers/pub/pubhealth/manprog/mhp.pdf (Accessed December 2007).

(15.) Ontario Ministry of Health and Long-Term Care. Ontario Public Health Standards, 2008. Available online at: http://www.health.gov.on.ca/english/providers/ program/pubhealth/oph_standards/ophs/progstds/pdfs/ophs_2008.pdf (Accessed July 30, 2008).

(16.) Ontario Ministry of Education. Policy/program Memorandum No. 138, 2005. Available online at: http://www.edu.gov.on.ca/extra/eng/ppm/138.html (Accessed October 19, 2005).

(17.) Hogwood BW, Gunn LA. Policy Analysis for the Real World. Oxford, UK: Oxford University Press, 1984.

(18.) Heck RH. Studying Educational and Social Policy: Theoretical Concepts and Research Methods. Mahwah, NJ: Lawrence Erlbaum Associates, Inc., 2004.

(19.) Gerston LN. Public Policy Making: Process and Principles, 2nd ed. New York: M.E. Sharpe, 2004.

(20.) McGraw SA, Sellers D, Stone E, Resnicow KA, Kuester S, Fridinger F, et al. Measuring implementation of school programs and policies to promote healthy eating and physical activity among youth. Prev Med 2000;31(Suppl):S86-S97.

(21.) Pal LA. Public Policy Analysis: An introduction, 2nd ed. Scarborough, ON: Nelson Canada, 1992.

(22.) Hill M, Hupe P. Implementing Public Policy. Thousand Oaks, CA: Sage Publications, 2002;50-51.

(23.) Levin B. Deputy Minister of Education: Memorandum to Directors of Education re: daily physical activity in elementary schools grades 1-8--Policy/Program Memorandum 138. Available online at: http://www.edu.gov.on.ca/eng/ teachers/directormemo.pdf (Accessed October 18, 2005).

(24.) Levin B. Deputy Minister of Education: Memorandum to Principals of elementary schools re: daily physical activity in elementary schools grades 1-8--Policy/Program Memorandum 138. Available online at: http://www.edu.gov.on.ca/eng/teachers/principalmemo.pdf (Accessed October 18, 2005).

(25.) Ontario Ministry of Education. Healthy schools condition healthy minds. Available online at: http://ogov.newswire.ca/ontario/GPOE/2005/10/06/ c8547.html?lmatch=%3C=_e.html (Accessed October 12, 2005).

(26.) Ontario Ministry of Education. Daily physical activity in schools: Grades 1-3 Resource Guide. 2005. Available online at: http://www.edu.gov.on.ca/eng/ teachers/dpa1-3.pdf (Accessed June 19, 2006).

(27.) Ontario Ministry of Education. Daily physical activity in schools: Grades 4-6 Resource Guide. 2005. Available online at: http://www.edu.gov.on.ca/eng/ teachers/dpa4-6.pdf (Accessed June 19, 2006).

(28.) Ontario Ministry of Education. Daily physical activity in schools: Grades 7-8 Resource Guide. 2005. Available online at: http://www.edu.gov.on.ca/eng/ teachers/dpa7-8.pdf (Accessed June 19, 2006).

(29.) Ontario Ministry of Education. Daily physical activity in schools: Guide for school boards. Available online at: http://www.edu.gov.on.ca/eng/teachers/ dpa_boards.pdf (Accessed June 19, 2006).

(30.) Ontario Ministry of Education. Daily physical activity in schools: Guide for principals. Available online at: http://www.edu.gov.on.ca/eng/teachers/ dpa_principals.pdf (Accessed June 19, 2006).

(31.) E-Learning module--Daily physical activity: Active today. Active for life! Available online at: http://www.eworkshop.on.ca/edu/dpa/intro.cfm (Accessed July 26, 2008).

(32.) Ontario Physical and Health Education Association. Daily physical activity update--May 1, 2006. Toronto: OPHEA, 2006.

(33.) Ontario Physical and Health Education Association. Daily physical activity update - February 21, 2007. Available online at: http://www.ophea.net// ophea/Ophea.net/upload/DPA-May-Announcement.pdf (Accessed September 1, 2007).

(34.) Barroso CS, McCullum-Gomez C, Hoelscher DM, Kelder SH, Murray NG. Selfreported barriers to quality physical education by physical education specialists in Texas. J Sch Health 2005;75:313-19.

(35.) Deacon BW. Physical Education Curriculum Review Report. Victoria, BC: Ministry of Education Curriculum Division, 2001. Available online at: http://www.bced.gov.bc.ca/irp/reports/pereport.pdf (Accessed October 19, 2005).

(36.) Hansen H. Barriers to QDPE and how to overcome them. CAHPERD Journal 1990;56:1621.

(37.) Humbert ML, Chad KE. Determining barriers to implementing quality daily physical education. ICHPERSD 1998;42:13-17.

(38.) Hardman K, Marshall J. The state and status of physical education in schools in international context. Euro Phys Educ Rev 2000;6:203-29.

(39.) People for Education. The annual report on Ontario's schools, 2008. Available online at: http://www.peopleforeducation.com/reportonschools08 (Accessed July 25, 2008).

(40.) Active Healthy Kids Canada. Canada's report card on physical activity for children & youth 2008. Available online at: http://www.activehealthykids.ca/ Ophea/ActiveHealthyKids_v2/upload/AHKC-Long-Form-EN.pdf (Accessed July 25, 2008).

(41.) Janssen I. Physical activity guidelines for children and youth. Appl Physiol Nutr Metab 2007;32:S109-S121.

(42.) Public Health Agency of Canada and Canadian Society for Exercise Physiology. Canada's Physical Activity Guide for Youth, 2002. Available online at: http://www.phac-aspc.gc.ca/pau-uap/paguide/child_youth/pdf/guide_y_e.pdf (Accessed July 25, 2008).

(43.) Public Health Agency of Canada and Canadian Society for Exercise Physiology. Canada's Physical Activity Guide for Children, 2002. Available online at: http://www.phac-aspc.gc.ca/pau-uap/paguide/child_youth/pdf/guide_k_e.pdf (Accessed July 25, 2008).

(44.) Mueller L. Gutted programs and children's guts. CMAJ 2008;178:665-67.

(45.) Canadian Association of Health, Physical Education, Recreation, and Dance. Quality daily physical education: About QDPE. Available online at: http://www.cahperd.ca/eng/physicaleducation/about_qdpe.cfm (Accessed June 2007).

(46.) Ramanathan S, Allison KR, Faulkner G, Dwyer JJM. Challenges in assessing the implementation and effectiveness of physical activity and nutrition policy interventions as natural experiments. Health Promot Int 2008;23:290-97.

(47.) Alberta Education. Daily physical activity initiative. Available online at: http://education.alberta.ca/teachers/resources/dpa.aspx (Accessed July 25, 2008).

(48.) Education Quality and Accountability Office. Available online at: http://www.eqao.com/categories/home.aspx?Lang=E (Accessed July 26, 2008).

Jennifer E. Robertson-Wilson, PhD, [1] Lucie Levesque, PhD [2]

Author Affiliations

[1.] Department of Kinesiology and Physical Education, Wilfrid Laurier University, Waterloo, ON

[2.] School of Kinesiology and Health Studies, Queen's University, Kingston, ON

Correspondence and reprint requests: Jennifer Robertson-Wilson, Department of Kinesiology and Physical Education, Wilfrid Laurier University, 75 University Ave. W, Waterloo, ON N2L 3C5, Tel: 519-884-0710, ext. 3928, Fax: 519-747-4594, E-mail: jrobertsonwilson@wlu.ca

Acknowledgements: This paper was drafted while Jennifer Robertson-Wilson was a doctoral student in the School of Kinesiology and Health Studies at Queen's University and under a Social Sciences and Humanities Research Council of Canada doctoral fellowship (# 752-2003-1338). The authors also acknowledge the helpful comments of Robert Wilson, Jessica Fraser-Thomas, Charles Ungerleider, and Kim Bergeron, and two anonymous reviewers on an earlier draft. Table 1. Hogwood and Gunn's * 10 Preconditions for Implementation Listed Verbatim Precondition 1. "The circumstances external to the implementing agency do not impose crippling constraints" 2. "That adequate time and sufficient resources are made available to the programme" 3. "That the required combination of resources is actually available" 4. "That the policy to be implemented is based upon a valid theory of cause and effect" 5. "That the relationship between cause and effect is direct and that there are few if any, intervening links" 6. "That dependency relationships are minimal" 7. "That there is understanding of, and agreement on, objectives" 8. "That tasks are fully specified in correct sequence" 9. "That there is perfect communication and co-ordination" 10. "That those in authority can demand and obtain perfect compliance" * Ref. 17, pp. 199-206.