Dairy products are a convenient source of vitamins, minerals, and protein necessary in the diets or pre-adolescents and adolescents [1Moore LL, Bradlee ML, Gao D, Singer MR. Effects of average childhood dairy intake on adolescent bone health. J Pediatr 2008; 153(5): 667-73.
[http://dx.doi.org/10.1016/j.jpeds.2008.05.016] [PMID: 18701115] , 2Park A, Nitzke S, Kritsch K, et al. Internet-based interventions have potential to affect short-term mediators and indicators of dietary behavior of young adults. J Nutr Educ Behav 2008; 40(5): 288-97.
[http://dx.doi.org/10.1016/j.jneb.2008.02.001] [PMID: 18725147] ]. However, despite the known health benefits of dairy products, their daily consumption continues to decline in many populations, particularly in pre-adolescents and adolescents. As dairy products are foods that promote health and prevent disease later in life, their low consumption is a concern for children and adolescents who are developing eating habits that will carry into adulthood. Therefore, it is of interest to investigate interventions and strategies to increase the knowledge and consumption of dairy products among pre-adolescents and adolescents.

Previous research has highlighted components and characteristics of nutrition interventions, including dairy, that are likely to be effective [3Hendrie GA, Brindal E, Baird D, Gardner C. Improving children’s dairy food and calcium intake: Can intervention work? A systematic review of the literature. Public Health Nutr 2013; 16(2): 365-76.
[http://dx.doi.org/10.1017/S1368980012001322] [PMID: 22607694] -5Racey M, O’Brien C, Douglas S, Marquez O, Hendrie G, Newton G. Systematic review of school-based interventions to modify dietary behavior: Does intervention intensity impact effectiveness? J Sch Health 2016; 86(6): 452-63.
[http://dx.doi.org/10.1111/josh.12396] [PMID: 27122145] ]. Schools are recognized as an appropriate setting and location to implement dietary interventions as they provide a place in which consistent and reliable information is delivered to students [6Brown T, Summerbell C. Systematic review of school-based interventions that focus on changing dietary intake and physical activity levels to prevent childhood obesity: An update to the obesity guidance produced by the National Institute for Health and Clinical Excellence. Obes Rev 2009; 10(1): 110-41.
[http://dx.doi.org/10.1111/j.1467-789X.2008.00515.x] [PMID: 18673306] ]. In addition, school-based interventions may be enhanced through the use of strategies that reach beyond the classroom, such as specialized web-based programs [7DeBar LL, Dickerson J, Clarke G, Stevens VJ, Ritenbaugh C, Aickin M. Using a website to build community and enhance outcomes in a group, multi-component intervention promoting healthy diet and exercise in adolescents. J Pediatr Psychol 2009; 34(5): 539-50.
[http://dx.doi.org/10.1093/jpepsy/jsn126] [PMID: 19091807] , 8Haerens L, De Bourdeaudhuij I, Maes L, Cardon G, Deforche B. School-based randomized controlled trial of a physical activity intervention among adolescents. J Adolesc Health 2007; 40(3): 258-65.
[http://dx.doi.org/10.1016/j.jadohealth.2006.09.028] [PMID: 17321427] ]. Nutrition sessions can be taught to all students in the classroom, and then students can be directed to web-based programs that they can access from home or other locations. These programs could be designed to supplement the material taught in class, using content that appeals to youth including games and other engagement strategies [9Racey M, Machmueller D, Field D, Kulak V, Newton GS. Perceptions and use of sources of health knowledge by young adolescents. Int J Adolesc Med Health 2016; 30(1)
[http://dx.doi.org/10.1515/ijamh-2016-0002] [PMID: 27299195] ]. Web-based programs may be especially appropriate for use in interventions targeting youth, as 93% of adolescents use the internet [10Lenhart A, Madden M, Rankin Macgill A, Smith A. Teens and social media: The use of social media gains a greater foothold in teen life as they embrace the conversational nature of interactive online media 2003.]. It has also been widely reported that adolescents are more comfortable with technologies like the Internet and perceive them as more helpful than do adults [11Macgill A. Parent and Teen Internet Use | Pew Research Center 2007. Available from: http://www.pewinternet.org/2007/10/24/parent-and-teen-internet-use/]. Supplementing a school-based nutrition intervention with a web-based program allows students to access the information at any time, and therefore increases potential exposure to the intervention content, which may facilitate changes in behaviour. In addition, the use of technology can allow further reach into the home environment through use of the web-based program at home and promotion of the technology through email correspondence with parents. However, there is a limited amount of literature evaluating websites or other technologies as supportive components of health or nutrition interventions, as the majority of these interventions are either strictly web-based or school-based.

Therefore, this study aimed to evaluate the voluntary use of the web-based component of the school-based WhyDairy? intervention. The primary objective of the WhyDairy intervention was to evaluate effectiveness related to knowledge and dairy intake behaviour, and is not reported here. The website component of the intervention provided an online, interactive learning environment to complement four informative in-school visits. We hypothesized that the novel school-based intervention would result in consistent use of the website and would be voluntarily accessed by a majority of students.

The purpose of this paper was to investigate the use of the WhyDairy? web-based component by students during the intervention and subsequent follow-up period. The timing of website sessions in comparison to classroom visits, popular website content and traversal paths through web pages were all topics of interest. Overall, participants demonstrated some voluntary use of the website, mostly during a two-day period following intervention education visits; however, voluntary engagement with the website during the intervention period was limited overall, and there was an almost total lack of engagement with the website during the follow-up period.

The amount of time spent on a website has been shown to be a significant indicator of behaviour change outcomes in health interventions [12Couper MP, Alexander GL, Zhang N, et al. Engagement and retention: Measuring breadth and depth of participant use of an online intervention. J Med Internet Res 2010; 12(4): e52.
[http://dx.doi.org/10.2196/jmir.1430] [PMID: 21087922] ]. One-third of our intervention study population voluntarily used the website during the eight-week intervention period, but activity almost exclusively occurred within two-days following a research visit. This may suggest that repeated between visit prompts or personalized sections of the website, such as recommended by DeBar et al. (2009), are warranted to encourage the sustained use of a supplementary web-based component of a school-based nutrition intervention. Of those who viewed the website, almost half were returning users which could indicate that these students found the website to be of interest and therefore chose to revisit. Although data regarding dietary intake are not reported here, it should be noted that when dairy intake was analyzed as an outcome of intervention effectiveness, there was no difference between the control and intervention groups, with neither group showing an increase in intake. The limited voluntary interaction with the WhyDairy? website outside of the classroom visits is consistent with the failure to change behaviour, as described by Couper et al. (2010). Due to the design of the present study, we were unable to explore the reasons for return visits, as Google Analytics provided us with anonymous usage of the website. As well, we were also unable to determine whether dairy intake on an individual level was positively associated with website use. These would certainly be topics to explore in future research, as it would be of value to determine whether website use predicted behavior in individuals, the characteristics of the returning users compared to those who did not return, their motivations to return to the webpage, and the specific website components that appealed most to users.

Using the WhyDairy? website as a supplementary, technological component to the school-based intervention had the added benefit that website content could be specifically matched to the content of the research visits. As well, the website was updated with new content prior to each research visit; that is, the sections of the website that were used as part of each classroom visit were not released to students in advance, but rather were released on the day of the visit. Previous research has demonstrated that users preferred having new, updated content throughout an intervention period and this encourages return visits to see the new content [13Papadaki A, Scott JA. Process evaluation of an innovative healthy eating website promoting the Mediterranean diet. Health Educ Res 2006; 21(2): 206-18.
[http://dx.doi.org/10.1093/her/cyh057] [PMID: 16199490] ]. The influence of face-to-face encouragement of using the website and the release of new content may have been related to a high number of visits within two days following a classroom visit and the relatively high number of returning users. However, we only successfully motivated one-third of students to visit the website, which means that the majority of students did not access the website on their own and may suggest that face-to-face encouragement, at least at a biweekly frequency, is not a sufficient engagement strategy.

In addition to visual appeal, the content and layout of a website can greatly influence which pages are visited. The high number of page views in the Interactive content category is consistent with previous research showing that children and adolescents enjoy games and interactive components of health and nutrition websites [14Ahn Y, Kim K-W. Study on utilization status of internet and needs assessment for developing nutrition education programs among elementary school children. Nutr Res Pract 2007; 1(4): 341-8.
[http://dx.doi.org/10.4162/nrp.2007.1.4.341] [PMID: 20368960] , 15Franck LS, Noble G. Here’s an idea: Ask the users! Young people’s views on navigation, design and content of a health information website. J Child Health Care 2007; 11(4): 287-97.
[http://dx.doi.org/10.1177/1367493507083941] [PMID: 18039731] ]. While the Kitchen/Recipe category had the second highest views, we are limited in not knowing if a student printed or recorded the recipe. The layout of the website may also promote page views for specific content categories. For example, one interactive feature in the WhyDairy? website involved exploration of the human body to learn how dairy and alternatives affect various body parts and bodily functions. Users were able to click on different parts for further information. Therefore, this feature promoted additional page views of the Interactive category as users explored many body parts. In contrast, most knowledge pages contained only information presented in text without links to additional knowledge pages. This is a caveat to consider when relying on categorical page view data to conclude about popular content and further support the need for qualitative research.

In an attempt to gather a more holistic view of how students navigated through the site, researchers utilized the Behaviour Flow tool of Google Analytics. This tool provided valuable insight towards how students navigated through the website, specifically the order by which they viewed different types of content and the pages from which they exited the website. This analysis is an example of combining the quantitative data collected by Google Analytics with objective interpretation to gain a more in-depth understanding of user behaviours. Our observations support the progression towards higher order learning during a website session. Bloom’s taxonomy outlines progression in thinking where a foundation of understanding developed in lower-order thinking is necessary to progress to higher order thinking [16Anderson LW, Krathwohl DRDR, Bloom BS. A taxonomy for learning, teaching, and assessing: A revision of Bloom’s taxonomy of educational objectives 2001.]. Levels of thinking progress in the following order: Remembering, Understanding, Applying, Analysing, Evaluating and Creating [16Anderson LW, Krathwohl DRDR, Bloom BS. A taxonomy for learning, teaching, and assessing: A revision of Bloom’s taxonomy of educational objectives 2001.]. When comparing the three content categories of the WhyDairy? website to Bloom’s Taxonomy levels, pages in the Knowledge category would fall under “Understanding” and Interactive pages would fall under “Applying”. Kitchen/Recipe pages would fall under “Creating”, as these pages provided recipes that students and their families could use to create meals or snacks. Here, students would have the opportunity to integrate their knowledge of dairy nutrition, such as nutritional benefits or serving sizes. Analysis of the traversal paths support the idea that users progressed in a pattern corresponding to Bloom’s Taxonomy levels, by building a foundation at the “Understanding” level before progressing to “Applying” or “Creating” levels. Researchers developing websites to assist in their intervention efforts may consider developing the pages to flow in the same order as Bloom’s Taxonomy in order to capitalize on student’s natural progression through the site and development of knowledge.

Another area of data that holds potential applications for website improvement is the section of the website from which students ended their session. While we were able to elicit a general percent exit rate based on content category (Table 5), we were also able to use the Behaviour Flow too to provide a more detailed view of website exits, by highlighting the depth of their website session when the student exited. Although the measurement of exit percentage provides information on the last page visited before exiting the website, we are not informed on the motivation behind the user exiting the website; they could have exited because they were satisfied with the content and information that they viewed, or because they were unsatisfied and exited the website to search for information elsewhere [17Crutzen R, Roosjen JL, Poelman J. Using Google Analytics as a process evaluation method for Internet-delivered interventions: An example on sexual health. Health Promot Int 2013; 28(1): 36-42.
[http://dx.doi.org/10.1093/heapro/das008] [PMID: 22377974] ]. The latter reason highlights the importance of first impressions of the website pages. A study conducted by Lindgaard et. al. [18Lindgaard G, Fernandes G, Dudekx C, Brow J. Attention web designers: You have 50 milliseconds to make a good first impression! Behav Inf Technol 2006; 25: 115-26.
[http://dx.doi.org/10.1080/01449290500330448] ] established that it takes a website user 50ms to assess visual appeal, suggesting that the desire to exit the website may be influenced by first impressions based on page layout and design. This is an area of investigation that would benefit from further qualitative research, as focus groups or user interviews would assist in developing a more in-depth understanding of the exit percentage measurements.

Table 5
Summary of findings: Effectiveness of the WhyDairy? intervention and the associated website and parent email components.

It has been suggested that interventions aimed at improving adolescents’ consumption of dairy products may be enhanced by including a parental component [6Brown T, Summerbell C. Systematic review of school-based interventions that focus on changing dietary intake and physical activity levels to prevent childhood obesity: An update to the obesity guidance produced by the National Institute for Health and Clinical Excellence. Obes Rev 2009; 10(1): 110-41.
[http://dx.doi.org/10.1111/j.1467-789X.2008.00515.x] [PMID: 18673306] , 19Hanson NI, Neumark-Sztainer D, Eisenberg ME, Story M, Wall M. Associations between parental report of the home food environment and adolescent intakes of fruits, vegetables and dairy foods. Public Health Nutr 2005; 8(1): 77-85.
[http://dx.doi.org/10.1079/PHN2005661] [PMID: 15705248] ]. The WhyDairy? intervention attempted to engage parents by including a parental email campaign as part of the intervention, although parents were only engaged following the completion of the school visits and not during the school visit period, and it should be noted that the parental email campaign took place in part over summer holidays, during which some families may have been away on vacation with limited Internet access. Nonetheless, it is evident that the parental email campaign during the follow-up period in this study was not effective at engaging the parents or children through the website, as evidenced by the extremely low number of website visits during the follow-up period by either INT or INT+FU groups. It is possible that more intensive engagement of parents during the intervention period, in addition to the follow-up period, would have been more effective. In contrast to website engagement, the follow-up email campaign was more successful at engaging parents to open the sent emails. Emails contained rich content related to dairy products and health, and while each contained links to the website, it is possible that the information contained within the email was deemed sufficient. Future research that incorporates parents as a target of web-based interventions should focus on actively engaging the parents, since changing the home food environment and utilizing parents to model healthy behaviours are predictors of behavior change [6Brown T, Summerbell C. Systematic review of school-based interventions that focus on changing dietary intake and physical activity levels to prevent childhood obesity: An update to the obesity guidance produced by the National Institute for Health and Clinical Excellence. Obes Rev 2009; 10(1): 110-41.
[http://dx.doi.org/10.1111/j.1467-789X.2008.00515.x] [PMID: 18673306] , 19Hanson NI, Neumark-Sztainer D, Eisenberg ME, Story M, Wall M. Associations between parental report of the home food environment and adolescent intakes of fruits, vegetables and dairy foods. Public Health Nutr 2005; 8(1): 77-85.
[http://dx.doi.org/10.1079/PHN2005661] [PMID: 15705248] , 20Arcan C, Neumark-Sztainer D, Hannan P, van den Berg P, Story M, Larson N. Parental eating behaviours, home food environment and adolescent intakes of fruits, vegetables and dairy foods: Longitudinal findings from Project EAT. Public Health Nutr 2007; 10(11): 1257-65.
[http://dx.doi.org/10.1017/S1368980007687151] [PMID: 17391551] ].

This study has several limitations. Firstly, the intervention program and time with the students were limited due to school board and individual school restrictions. This limited the length, depth, and intensity of the intervention, which have been suggested as important components for the success of changing adolescent behaviour [4Marquez O, Racey M, Preyde M, Hendrie G, Newton G. Interventions to increase dairy consumption in adolescents : A systematic review. ICAN Infant, Child. Adolesc Nutr 2015; 7: 242-54.
[http://dx.doi.org/10.1177/1941406415600752] , 5Racey M, O’Brien C, Douglas S, Marquez O, Hendrie G, Newton G. Systematic review of school-based interventions to modify dietary behavior: Does intervention intensity impact effectiveness? J Sch Health 2016; 86(6): 452-63.
[http://dx.doi.org/10.1111/josh.12396] [PMID: 27122145] ]. Secondly, Google Analytics was configured to distinguish each school’s activity via this specific web address; however, it did not allow us to identify specific website users and it is possible that the website may have been accessed by third-party users via Google search or ad buttons. In order to mitigate this, any Google Analytics data that appeared to originate from these third-party users were excluded from data analysis. We acknowledge the fact that those voluntarily accessing the intervention website represent a subset of the entire population and were likely more engaged students. Lastly, as already described, the anonymous nature of data collection through Google Analytics, which meant that analysis on an individual level to link website use with behaviour change was not possible.

Overall, the results of this study provide supportive evidence that incorporation of a voluntary web-based component with a school-based nutrition intervention can engage students, especially during the intervention period, although it is clear that not all students were motivated to explore the website on their own. Students were especially motivated to explore the website in the two days following a research visit. This engagement did not continue through the follow-up period, which included the summer break and a potential change in routine or access to internet. Finally, while parents were receptive to receiving emails as a follow-up strategy, the vast majority of parents did not engage with the email by clicking on any links or resources provided within the email text. Future research should consider the school environment as an effective location to educate students about foods for health and could supplement the lessons with web-based components. In addition, researchers should investigate motivations for using websites and how to encourage prolonged website use when developing these supportive intervention components. Parents have been shown to be an effective supplement to school-based interventions, and more targeted approaches that actively engage parents to engage with an intervention website may result in changes amongst students in future research.