How unit 3 is examined
This unit covers web metrics, reports and Google Analytics, KPIs, network measures and random graphs, social context, analytics tools and NLP for short text; no topic was asked recently, so each is short but complete.
Common Metrics: Hits, Page Views, Visits, Unique Page Views, Bounce, Bounce Rate & its Improvement, Average Time on Site
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Definition. <mark>Common web metrics are the basic counts and ratios that measure how much traffic a site receives and how visitors behave on it.</mark>
Key points.
- A hit is any single file request to the server (page, image, script), so it overstates real traffic; a page view counts one page load, and a unique page view counts a page once per visit.
- A visit is one session of activity by a visitor; a bounce is a visit that views only one page and leaves.
- Bounce rate = (single-page visits / total entry visits) x 100; improve it with faster loading, relevant content, clear calls to action and better navigation.
- Average time on site = total duration of all visits / number of visits.
Real Time Report, Traffic Source Report, Custom Campaigns, Content Report, Google Analytics
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Definition. <mark>Google Analytics is a free tool that collects visitor data with a JavaScript tag and presents it in reports on audience, traffic sources and content.</mark>
Key points.
- The real-time report shows users active on the site right now, with their pages, locations and sources.
- The traffic source report shows where visitors came from: organic search, direct, referral, social or paid.
- Custom campaigns tag URLs with UTM parameters (source, medium, campaign) so each marketing effort is tracked separately.
- The content report shows page views, time on page and bounce rate per page, revealing which content works.
Key-Performance Indicator: Need, Characteristics, Perspective and Uses
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Definition. <mark>A KPI is a measurable value that shows how effectively a business is achieving a key objective.</mark>
Key points.
- KPIs are needed because raw metrics do not show progress; KPIs tie numbers to goals and support decisions.
- Good KPIs are specific, measurable, relevant to goals, timely and actionable, and they are usually ratios or rates.
- Perspective: a KPI is chosen per business goal (sales, leads, engagement, support), e.g. conversion rate for e-commerce.
- Uses: tracking progress, benchmarking, spotting problems early and justifying spend.
Graphs and Matrices: Basic Measures for Individuals and Networks
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Definition. ==A social network is a graph of nodes (people) and edges (ties), stored as an adjacency matrix where entry $a_{ij}=1$ if $i$ and $j$ are linked.==
Key points.
- Degree of a node is its number of ties; degree centrality = $\deg(v)/(n-1)$.
- Closeness centrality measures how near a node is to all others; betweenness measures how often it lies on shortest paths between others.
- Network density = $2m/(n(n-1))$ for $m$ edges and $n$ nodes.
- Clustering coefficient shows how many of a node's neighbours are also linked to each other.
Random Graphs & Network Evolution
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Definition. <mark>An Erdos-Renyi random graph $G(n,p)$ has $n$ nodes in which each possible edge exists independently with probability $p$.</mark>
Key points.
- Expected number of edges is $p\,n(n-1)/2$ and expected degree is $p(n-1)$.
- Degrees follow a binomial (about Poisson) distribution, so random graphs have no hubs.
- Real networks evolve by growth and preferential attachment, where new nodes link to popular nodes, giving power-law degrees.
- Real networks show small-world behaviour: short paths and high clustering.
Social Context: Affiliation & Identity
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Definition. <mark>Social context is the set of groups, affiliations and identities that shape who people connect with and how they behave online.</mark>
Key points.
- Affiliation networks link people to groups or events they share, such as pages, clubs or hashtags.
- Identity is how a person presents and is categorised, through profile, interests and group membership.
- Homophily is the tendency of similar people to connect, so shared affiliation predicts ties.
- Influence and selection both create similar neighbours: people befriend similar people and also become like their friends.
Web analytics Tools: A/B testing, Online Surveys, Web Crawling and Indexing
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Definition. <mark>Web analytics tools are methods that test, ask or collect data to understand and improve a website.</mark>
Key points.
- A/B testing shows two page versions to random visitor halves and picks the one with the better conversion rate.
- Online surveys ask visitors directly, giving qualitative reasons that numbers cannot show.
- Web crawling is automated fetching of pages by following links.
- Indexing stores the crawled content in a searchable structure so a search engine can retrieve pages by keyword.
Natural Language Processing Techniques for Micro-Text Analysis
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Definition. <mark>Micro-text analysis applies NLP to very short, noisy texts such as tweets and comments to extract meaning, topics and sentiment.</mark>
Key points.
- Preprocessing cleans the text by tokenisation, lowercasing, stop-word removal and stemming, and handles hashtags, emoticons and slang.
- Sentiment analysis classifies text as positive, negative or neutral using lexicons or machine learning.
- Named entity recognition and topic modelling find people, brands and themes in posts.
- Short length and sparse context make accuracy lower than for long documents.
Last-minute revision
- Hit = any file request; page view = one page load; unique page view = page counted once per visit.
- Bounce rate = single-page visits / entry visits x 100.
- Average time on site = total visit time / number of visits.
- GA reports: real time, traffic source, content; UTM tags track custom campaigns.
- KPI = measurable value tied to a business goal.
- Degree centrality = deg/(n-1); density = 2m/(n(n-1)).
- Random graph $G(n,p)$: expected edges $p\,n(n-1)/2$.
- Preferential attachment gives power-law degrees; homophily means like connects with like.
- A/B testing compares two versions by conversion rate.
- Crawl, then index, then search.
- Micro-text NLP: preprocess, then sentiment, entities and topics.
Memory hooks
- Hits are noisy, page views are cleaner, visits are sessions.
- KPI = Key number tied to a Purpose and an Indicator of progress.
- Erdos-Renyi is random with no hubs; rich-get-richer creates hubs.
- Crawl finds, index files, search fetches.
Coverage checklist
- Common Metrics: Hits, Page Views, Visits, Unique Page Views, Bounce, Bounce Rate & its Improvement, Average Time on Site (no past questions).
- Real Time Report, Traffic Source Report, Custom Campaigns, Content Report, Google Analytics (no past questions).
- Key-Performance Indicator: Need, Characteristics, Perspective and Uses (no past questions).
- Graphs and Matrices- Basic Measures for Individuals and Networks (no past questions).
- Random Graphs & Network Evolution (no past questions).
- Social Context: Affiliation & Identity (no past questions).
- Web analytics Tools: A/B testing, Online Surveys, Web Crawling and Indexing (no past questions).
- Natural Language Processing Techniques for Micro-Text Analysis (no past questions).