Uploaded by Mashrekul Kabir

Sentiment Analysis

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https://searchbusinessanalytics.techtarget.com/definition/opinion-mining-sentiment-mining
Metadata is data that describes other data. Meta is a prefix that in most
information technology usages means "an underlying definition or description."
Metadata summarizes basic information about data, which can make finding and
working with particular instances of data easier. For example, author, date
created and date modified and file size are examples of very basic document
metadata. Having the abilty to filter through that metadata makes it much easier
for someone to locate a specific document.
In addition to document files, metadata is used for images, videos, spreadsheets
and web pages. The use of metadata on web pages can be very important.
Metadata for web pages contain descriptions of the page’s contents, as well as
keywords linked to the content. These are usually expressed in the form
of metatags. The metadata containing the web page’s description and summary
is often displayed in search results by search engines, making its accuracy and
details very important since it can determine whether a user decides to visit the
site or not. Metatags are often evaluated by search engines to help decide a web
page’s relevance, and were used as the key factor in determining position in a
search until the late 1990s. The increase in search engine optimization (SEO)
towards the end of the 1990s led to many websites “keyword stuffing” their
metadata to trick search engines, making their websites seem more relevant than
others. Since then search engines have reduced their reliance on metatags,
though they are still factored in when indexing pages. Many search engines also
try to halt web pages’ ability to thwart their system by regularly changing their
criteria for rankings, with Google being notorious for frequently changing their
highly-undisclosed ranking algorithms.
Metadata can be created manually, or by automated information processing.
Manual creation tends to be more accurate, allowing the user to input any
information they feel is relevant or needed to help describe the file. Automated
metadata creation can be much more elementary, usually only displaying
information such as file size, file extension, when the file was created and who
created the file.
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Unstructured text is written content that lacks metadata and cannot readily be
indexed or mapped onto standard database fields. It is often user-generated
information such as email or instant messages, documents or social
media postings. Unstructured text is an important source of information for
businesses, research institutes and surveillance agencies. Enterprises often
mine unstructured text for data to enhance their business intelligence strategy
and gain a competitive advantage in the marketplace. The unstructured text
collected from social media activities plays a key role in predictive analytics for
the enterprise because it is a prime source for sentiment analysis to determine
the general attitude of consumers toward a brand or idea.
Mining of unstructured text delivers new insights by uncovering previously
unknown information, detecting patterns and trends, and identifying connections
between seemingly unrelated pieces of data. Natural language
processing software and other automated tools are typically used to prepare
unstructured text for indexing. Because language is often vague, disambiguation
of the text through an examination of context is often an important initial step in
the mining process. The content is also reviewed for word frequency and other
patterns. Tagging is performed to label various pieces of text-derived data so it
can be categorized and grouped in ways that are most likely to deliver useful
information. Once the text has been turned into data, it can be analyzed and
evaluated for relevance and importance.
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Sentiment analysis, also referred to as opinion mining, is an approach to natural
language processing (NLP) that identifies the emotional tone behind a body of
text. This is a popular way for organizations to determine and categorize opinions
about a product, service or idea. It involves the use of data mining, machine
learning (ML) and artificial intelligence (AI) to mine text for sentiment and
subjective information.
Sentiment analysis systems help organizations gather insights
from unorganized and unstructured text that comes from online sources such as
emails, blog posts, support tickets, web chats, social media channels,
forums and comments. Algorithms replace manual data processing by
implementing rule-based, automatic or hybrid methods. Rule-based systems
perform sentiment analysis based on predefined, lexicon-based rules while
automatic systems learn from data with machine learning techniques. A hybrid
sentiment analysis combines both approaches.
In addition to identifying sentiment, opinion mining can extract the polarity (or the
amount of positivity and negativity), subject and opinion holder within the text.
Furthermore, sentiment analysis can be applied to varying scopes such as
document, paragraph, sentence and sub-sentence levels.
Vendors that offer sentiment analysis platforms or SaaS products include
Brandwatch, Hootsuite, Lexalytics, NetBase, Sprout Social, Sysomos and Zoho.
Businesses that use these tools can review customer feedback more regularly
and proactively respond to changes of opinion within the market.
Types of sentiment analysis
1. Fine-grained sentiment analysis provides a more precise level of polarity by breaking
it down into further categories, usually very positive to very negative. This can be
considered the opinion equivalent of ratings on a 5-star scale.
2. Emotion detection identifies specific emotions rather than positivity and negativity.
Examples could include happiness, frustration, shock, anger and sadness.
3. Intent-based analysis recognizes actions behind a text in addition to opinion. For
example, an online comment expressing frustration about changing a battery could
prompt customer service to reach out to resolve that specific issue.
4. Aspect-based analysis gathers the specific component being positively or negatively
mentioned. For example, a customer might leave a review on a product saying the
battery life was too short. Then, the system will return that the negative sentiment is
not about the product as a whole, but about the battery life.
Applications of sentiment analysis
Sentiment analysis tools can be used by organizations for a variety of applications,
including:

Identifying brand awareness, reputation and popularity at a specific moment or over
time.

Tracking consumer reception of new products or features.

Evaluating the success of a marketing campaign.

Pinpointing the target audience or demographics.

Collecting customer feedback from social media, websites or online forms.

Conducting market research.

Categorizing customer service requests.
Challenges with sentiment analysis
Challenges associated with sentiment analysis typically revolve around inaccuracies in
training models. Objectivity, or comments with a neutral sentiment, tend to pose a
problem for systems and are often misidentified. For example, if a customer received the
wrong color item and submitted a comment "The product was blue," this would be
identified as neutral when in fact it should be negative.

Margaret Rouse asks:
What is the most valuable insight that
sentiment analysis helps your organization
gather?
Join the Discussion
Sentiment can also be challenging to identify when systems cannot understand the
context or tone. Answers to polls or survey questions like "nothing" or "everything" are
hard to categorize when the context is not given, as they could be labeled as positive or
negative depending on the question. Similarly, irony and sarcasm often cannot be
explicitly trained and lead to falsely labeled sentiments.
Computer programs also have trouble when encountering emojis and irrelevant
information. Special attention needs to be given to training models with emojis and
neutral data so as to not improperly flag texts.
Finally, people can be contradictory in their statements. Most reviews will have both
positive and negative comments, which is somewhat manageable by analyzing sentences
one at a time. However, the more informal the medium (Twitter or blog posts, for
example), the more likely people are to combine different opinions in the same sentence
and the more difficult it will be for a computer to parse.
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