HTN planning: Overview, comparison, and beyond

Hierarchies are one of the most common structures used to understand and conceptualise the world. Within the field of Artificial Intelligence (AI) planning, which deals with the automation of world-relevant problems, Hierarchical Task Network (HTN) planning is the branch that represents and handles hierarchies. In particular, the requirement for rich domain knowledge to characterise the world enables HTN planning to be very useful, and also to perform well. However, the history of almost 40 years obfuscates the current understanding of HTN planning in terms of accomplishments, planning models, similarities and differences among hierarchical planners, and its current and objective image. On top of these issues, the ability of hierarchical planning to truly cope with the requirements of real-world applications has been often questioned. As a remedy, we propose a framework-based approach where we first provide a basis for defining different formal models of hierarchical planning, and define two models that comprise a large portion of HTN planners. Second, we provide a set of concepts that helps in interpreting HTN planners from the aspect of their search space. Then, we analyse and compare the planners based on a variety of properties organised in five segments, namely domain authoring, expressiveness, competence, computation and applicability. Furthermore, we select Web service composition as a real-world and current application, and classify and compare the approaches that employ HTN planning to solve the problem of service composition. Finally, we conclude with our findings and present directions for future work. In summary, we provide a novel and comprehensive viewpoint on a core AI planning technique.<br/

Advising Assessment Practices of Advising Professionals at an Accredited United Kingdom Urban Career-Focused Higher Education Institution: A Replicated Quantitative, Descriptive Analysis

The Problem As the world has flattened, the globalization and quality education movement surrounding higher education worldwide has led to the accountability of all stakeholders regarding student success in and beyond the classroom. Student mobility continues to impact tertiary enrollments as families and students consider the proliferated traditional and non-traditional enrollment alternatives along with prospective lower tertiary debt options. Although assessment, an accountability tool, in co-curricular areas such as advising has been overlooked by leaders, advising is not impervious to accountability consequences. The problem is that assessment of advising, if performed, is oftentimes implemented informally, without a well-defined framework or the utilization of sophisticated measures, consequently advancing uninformed decisions that may have adverse effects on student success. This study examined the advising assessment practices (identify SLOs, determine assessment method(s) used, and utilize assessment data) of an accredited urban careerfocused university with a student body comprised of over 30% non-natives representing 65 countries and located in the United Kingdom; a country identified as the second most popular tertiary mobile student enrollment destination, in a time when tertiary student success is under intense scrutiny. Method An online, validated, cross-sectional National Survey on Assessment of Academic Advising instrument was slightly revised and used for this replicated study to gain a fundamental cross-cultural understanding of advising assessment practices from the viewpoint of advising professionals having responsibilities associated with undergraduate advising at one U.K. university. Three of the four research questions focused on advising assessment practices and included: 1. What are the advising student learning outcomes identified at the participating U.K. university? 2. What are the advising methods utilized to conduct assessment of advising SLOs at the participating U.K. university? and 3. How are the advising assessment data used for advising co-curricular improvement(s) at the participating U.K. university? The fourth question focused on the advising professional’s assessment perceptions and included: 4. What elements are viewed as supporting the assessment of advising at the participating U.K. university? All response data were analyzed using descriptive statistics. The nominally measured independent variables included the three recognized assessment practices of: 1) identifying advising SLOs, 2) employing assessment method(s), and 3) utilizing advising assessment data. The 26 pre-defined advising student learning outcomes that articulate what students are expected to know (cognitive learning), do (behavioral learning), and value (affective learning) were the nominally measured dependent variables (Powers, 2012, p. 15). Findings The findings indicated that the European university informally assessed advising through the three observed advising assessment practices. The sample reporting described cognitive learning outcomes as the most identified advising learning outcomes; focused on what students should know as a result of advising (Powers, 2012, p. 40). The data also revealed that surveys/questionnaires were the advising assessment method identified with the highest frequency within all the advising student learning outcomes, and the main use for advising assessment data for both cognitive and behavioral advising student learning outcomes was to improve advising process/delivery, whereas the primary assessment data use for affective student learning outcomes was to improve advising curriculum. Furthermore, the results suggested the four main elements perceived as important in supporting advising assessment were: advisors needed to believe that advising assessment was a worthwhile endeavor, advisors need to know how to conduct assessment of advising, advisors need to feel confident in their abilities to properly conduct assessment of advising, and that advisors need more information about what similar universities are doing to assess advising. Whereas, respondents indicated the most neutral view of the element: advisors need to be rewarded for assessment of advising activities, and interestingly, revealed that advisors need to enjoy the assessment of advising process as unimportant in supporting the assessment of advising (Powers, 2012). Conclusions The research data suggests that the university informally exercised the steps identified as best practices in measuring the effect of advising on student learning. Moreover, with approximately 85% of respondents indicating the 7 cognitive, 11 behavioral and 8 affective learning outcomes were informally assessed implying an opportunity to formalize a culture of advising assessment. Additionally, the data suggests the leading perceptions of advisors needing to believe that advising assessment was a worthwhile endeavor, advisors needing to know how to conduct assessment of advising, advisors needing to feel confident in their abilities to properly conduct assessment of advising, and advisors needing more information about what similar universities are doing to assess advising as important factors in supporting advising assessment (Powers, 2012). This would involve a need for an internal strengths, weaknesses, opportunities and threats (SWOT) analysis of administration\u27s current support for advising assessment practices (Hladchenko, 2014). Furthermore, as the first study to examine the advising assessment practices of one European university, this study begins to addresses the current gap in published research regarding co-curricular assessment practices that creates a hindrance in replicating applicable cross-cultural advising assessment practices by seeking to establish commonalities between cultures yet also seeking to identify areas of difference within the global higher education community in support of student success (Newell, 1998, p. 359)