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Title
Course opinion mining methodology for knowledge discovery, based on
web social media
AuthorsSotirios Kontogiannis
Ioannis KazanidisStavros ValsamidisAlexandros Karakos
PCI 2014 Quality in Education Technologies
Outline
PCI 2014 Quality in Education Technologies
• Introduction
• Method
• Case study
• Results
• Proposed framework
• Proposed opinion mining system architecture
• Discussion and conclusions
Introduction
PCI 2014 Quality in Education Technologies
Primarily, authors used the LMS
platforms of academic institutions
where course knowledge and course
interest collide (apart from the
classroom)
Then the authors focused on student-
course appreciation by using
questionnaires and course grades
The results of this twofold evaluation
were sometimes contradicting
Introduction
PCI 2014 Quality in Education Technologies
Since LMS course evaluation is based
on a scientific evaluation approach,
authors concluded that a similar
approach is needed to replace the
questionnaires with a less guided and
manipulous scientific methodology
That is, knowledge extraction and
discovery from existing social networks
where people express freely and non
guided opposition for an academic
course
Introduction
PCI 2014 Quality in Education Technologies
This paper This paper proposes a framework for
applying opinion mining in social networks.
The goals of the proposed framework is to
(a) extract useful textual information from social networks of blogs regarding learning course activities or processes and (b) apply opinion mining techniques
on the extracted text in order to discover the positive or negative opinions concerning each course.
Framework
PCI 2014 Quality in Education Technologies
The 4 steps for opinion mining in a
social network
Case study
PCI 2014 Quality in Education Technologies
Study population and context
a microblog by following posts relative to the
educational level and institutional services of a Greek
Technological Educational Institute (TEI)
a period of six months
comments of different commentators from the
same department in the Greek language
It can be accessed at https://www.facebook.com/
groups/69887509784/
Case study
PCI 2014 Quality in Education Technologies
1st process Create, train and store the classification model for automatic categorization of text as positive or negative
Case study
PCI 2014 Quality in Education Technologies
2nd process Apply the model to new data to automatically be categorized into positive and negative
Results
PCI 2014 Quality in Education Technologies
Words like “painful”, “discourage”, “damage”,
“unemployment”, etc. were found to have negative sentiment
whereas words like “profitability”, “prosperity”, “interest”,
“success”, etc. were found to have positive sentiment in
comments.
The comments from the microblog of our study were split in
half between positive and negative about the educational
institute offered services and knowledge.
In other words our sample was split evenly on feelings.
PCI 2014 Quality in Education Technologies
Twofold methodology for the evaluation of an academic course LMS course web usage mining evaluation process
with the use of a three tier evaluation architecture and the measures, metrics and algorithms
Opinion mining process Proposed Framework
PCI 2014 Quality in Education Technologies
Opinion mining process Step 1
Source selection and monitoring of UGC sources educational institution channels general source channels
Step 2
Source crawling engine and initialization mechanism -
crawling design and crawled content storage
capabilities
Proposed Framework
PCI 2014 Quality in Education Technologies
Opinion mining process Step 3
Semantic enrichment engine – semantic
enrichment design If the text content is semi-structured, then the use of
either natural language processing (NLP) or other text analysis techniques in order to interpret (grammatically and syntactically process) each sentence, prior to the assignment if possible a sentiment to it
The effectiveness of the different approaches largely depends on the quality of the raw text to be analyzed; in general, NLP and therefore semantic enrichment is effective on syntactically-correct texts while it falls short on ill-formed sentences or when Internet dialects are used
Proposed Framework
PCI 2014 Quality in Education Technologies
Opinion mining process Step 4
Sentiment Analysis processes, metrics and
algorithms This step involves the use of opinion mining over a
adequate level of enriched sentences of user text. For this process to be accurate a very well trained dataset of opposite and negative sentences is required, with a high level of polarity among those datasets
For such functionality to be performed in an automatic and real-time manner or even to be a self trained feedback mechanism, appropriate metrics or scores need to be defined as well polarity judgment algorithms need to be proposed and validated
Proposed Framework
PCI 2014 Quality in Education Technologies
Opinion mining process Step 4
Sentiment Analysis processes, metrics and algorithms
If a polarized dataset of high confidence is pertained, then using a Part Of Speech sentence (POS) tagger (or NLP clustering of a sentence) and a trained Bayesian sentence classifier, we can pinpoint that a sentence tokens belong to a class of sentences by looking at the tokens probability
The likelihood of a sentence can be calculated to be negative as the number of negative sentences in that class over the total number of negative sentences in all classes
Likelihood_sentence_Negative = Number of class negative sentences / Total number of Negative sentences
Proposed Framework
PCI 2014 Quality in Education Technologies
Opinion mining process Step 5
Visualization and courses ranking mechanism
based on opinion results
Proposed Framework
PCI 2014 Quality in Education Technologies
This paper proposes a framework and a testbed system used for
applying opinion mining in blogs regarding course educational content.
a context sensitive sentiment analysis methodology which provides human like sentiment analysis based on semi supervised learning structures
Discussion and
Conclusion
PCI 2014 Quality in Education Technologies
The expected benefits of applying such a framework are the following: Qualitative presentation of people concerns
over a course and course user preferences. Recording user’s problems and negative or
positive user opinions concerning educational courses they are interested in without spatial and temporal restrictions
Discussion and
Conclusion
Discussion
PCI 2014 Quality in Education Technologies
Research Limitations The accuracy of the WSD (Word Sense
Disambiguation) program (OpenNLP) within this approach, so that the exact sense of each term can be identified and exact sentiment scores can be calculated
The framework has been only applied to a specific microblog for a set of three courses. In order to better benchmark it, it must be also applied to other blogs as well