Unit 3 & Unit 4
Visual Study Notes
P.R. Pote Patil College of Engineering & Management, Amravati Β· Sem II 2025β26
| Term | One-Line Definition | Example |
|---|---|---|
| Population | All elements sharing a common characteristic | All MBA students in Maharashtra |
| Sample | A smaller selected group from population | 200 MBA students from 5 Amravati colleges |
| Sampling Frame | Complete list from which sample is drawn | Registered MBA students list |
| Sampling Unit | Single element selected in the sample | Each individual student |
| Parameter (ΞΌ, Ο) | Describes the population β usually unknown | Avg income of ALL Infosys employees |
| Statistic (xΜ, s) | Describes the sample β calculated from data | Avg income of 500 surveyed employees |
| Sampling Error | Difference: sample statistic vs population parameter | Reduced by β sample size |
| Non-Sampling Error | Mistakes in collection / measurement β not sampling | Respondent misunderstands a question |
| Sampling Bias | Systematic error making sample unrepresentative | Over/under-representing a group |
| Census | Study every single element of the population | India's Population Census every 10 years |
Greek letters (ΞΌ, Ο) for Population Β· English letters (xΜ, s) for Sample
Every unit has a known, non-zero chance of selection. Results CAN be statistically generalized. β Preferred for quantitative, conclusive research. (Brayman & Bell)
Every unit has an equal & independent probability of selection β like a lottery.
Pick first unit randomly, then every kth unit after it.
Divide population into strata (non-overlapping subgroups), then randomly sample from each.
Divide into clusters (geographic/natural). Randomly select clusters β study ALL units within selected clusters.
Extension of cluster sampling β sampling occurs in multiple stages, progressively narrowing down. Most practical for large national surveys. (Cooper & Schindler)
NASSCOM: randomly pick 10 states from 28
From each state, randomly select 5 cities
From each city, randomly select 10 companies
From each company, randomly select 20 employees
Selection based on judgment, convenience, or criteria β NOT random chance. Results CANNOT be statistically generalized. β Used in exploratory, qualitative research. (Brayman & Bell)
Also called Accidental Sampling. Select units that are most easily accessible.
Best for: Pilot studies, pre-testing questionnaires
Researcher deliberately selects units they believe are most relevant and informative.
Non-probability version of stratified sampling. Researcher fills fixed quotas from each subgroup by any convenient means.
Also called Chain Referral Sampling. Start small β existing respondents refer others β sample grows like a snowball.
| Basis | π² Probability | π€ Non-Probability |
|---|---|---|
| Selection | Random, based on chance | Non-random, judgment/convenience |
| Equal Chance? | Known probability | Unknown probability |
| Generalizability | Can generalize β | Cannot generalize statistically β |
| Bias | Less biased | More prone to bias |
| Cost | More expensive, time-consuming | Cheaper, faster |
| Use Case | Quantitative, conclusive research | Qualitative, exploratory research |
| Examples | SRS, Stratified, Cluster, Systematic | Convenience, Purposive, Quota, Snowball |
No effect, no difference, no relationship. The default assumption β the status quo. Researcher tries to disprove this.
- Symbol: Hβ (H-naught)
- Example: Average exam score = 60 marks (ΞΌ = 60)
- Example: No significant difference in sales before/after ad campaign
Effect exists, difference exists, relationship exists. What researcher wants to prove. Supported when Hβ is rejected.
- Symbol: Hβ or Hβ
- Two-tailed: ΞΌ β 60 (either direction)
- One-tailed right: ΞΌ > 60 (greater than)
- One-tailed left: ΞΌ < 60 (less than)
False Positive
"We wrongly rejected a true Hβ"
Probability = Ξ±
Power of test = 1 β Ξ²
Confidence = 1 β Ξ±
False Negative
"Missed a real effect"
Probability = Ξ²
Type II = Telling an infected person they're healthy (missed detection) β MORE DANGEROUS in medicine!
Clearly define what you are testing and in which direction.
Usually Ξ± = 0.05 (5%) in business research. β 95% confidence.
Z-test / t-test / F-test / Chi-square β based on data type and sample size.
Look up statistical table using Ξ± and degrees of freedom.
Use sample data to compute the test statistic value.
If calculated value > critical value β REJECT Hβ. Else β Fail to Reject Hβ. Same rule: if p-value < Ξ± β REJECT Hβ.
Interpret results in the context of the research question in plain language.
Used when n β₯ 30 and population standard deviation (Ο) is known. Uses the standard normal distribution.
| Test Type | Ξ±=0.05 | Ξ±=0.01 |
|---|---|---|
| Two-tailed | Β±1.96 | Β±2.576 |
| One-tailed Right | +1.645 | +2.326 |
| One-tailed Left | β1.645 | β2.326 |
Z = (5200β5000) Γ· (600Γ·β36) = 200Γ·100 = 2.0
Critical value (two-tailed, Ξ±=0.05) = Β±1.96. Since |Z|=2.0 > 1.96 β REJECT Hβ
β Conclusion: Sales ARE significantly different from βΉ5000.
Used when n < 30 OR Ο is unknown. Uses t-distribution (thicker tails = more uncertainty). As nβ, t-distribution β normal distribution. (G.C. Beri)
- One-sample t-test: Compare sample mean to known value
- Independent samples: Compare two different groups
- Paired t-test: Before & after on SAME group
t = (5.2β6) Γ· (1.2Γ·β16) = β0.8Γ·0.3 = β2.67 df=15
Critical t (df=15, Ξ±=0.05, two-tailed) = Β±2.131. Since |t|=2.67 > 2.131 β REJECT Hβ
β Students study significantly FEWER than 6 hours per day.
Compare means of 3 or more groups simultaneously. Doing multiple t-tests instead would increase Type I error! (Cooper & Schindler)
F-value is always POSITIVE. Larger F = larger group differences.
- One-Way ANOVA: 1 independent variable
- Two-Way ANOVA: 2 independent variables
- Also used in regression analysis
Hβ: ΞΌNorth = ΞΌSouth = ΞΌWest Hβ: At least one is different.
β οΈ Important: F-test only tells you THAT a group is different β NOT WHICH groups differ. Use post-hoc tests (Tukey's HSD / Bonferroni) to find which ones.
Most important non-parametric test. Works with CATEGORICAL data (not numbers β categories). "One of the most useful tools in attribute data analysis." β G.C. Beri
df = (rowsβ1) Γ (colsβ1)
- Goodness of Fit: Do observed frequencies match expected? (1 variable)
- Test of Independence: Are 2 categorical variables associated? (Most common)
Hβ: ChatGPT usage and stream are independent. Hβ: They are associated.
df = (2β1)Γ(3β1) = 2. Critical ΟΒ² at Ξ±=0.05 = 5.991
If calculated ΟΒ² > 5.991 β REJECT Hβ β ChatGPT usage IS associated with stream of study!
| Feature | Z-Test | t-Test | F-Test (ANOVA) | ΟΒ² Chi-Square |
|---|---|---|---|---|
| Data Type | Quantitative | Quantitative | Quantitative | Categorical |
| Sample Size | Large (nβ₯30) | Small (n<30) | Any | Large (Eβ₯5) |
| Ο Known? | Yes | No | N/A | N/A |
| Groups | 1 or 2 | 1 or 2 | 3 or more | Association |
| Distribution | Normal (Z) | t-distribution | F-distribution | ΟΒ² distribution |
| Formula | (xΜβΞΌβ)/(Ο/βn) | (xΜβΞΌβ)/(s/βn) | MSB/MSW | Ξ£(OβE)Β²/E |
| Example | Sales vs target | Pre vs post training | Sales across regions | Gender vs preference |
Expert audiences β researchers, academics, specialists. Very detailed, full statistical analysis, technical jargon.
Non-expert audiences. Simple language, lots of visuals (charts, infographics), avoids technical jargon.
Written for decision-makers. Concise, action-oriented, focuses on implications & recommendations. Technical details in appendix.
Written during research to update clients/supervisors. No final conclusions yet.
Most rigorous. Strict institutional guidelines. Includes all components in detail. For degree requirements.
Background Β· Statement of Problem Β· Research Objectives Β· Research Questions Β· Significance Β· Scope & Limitations Β· Chapter Plan
Cover all major previous studies Β· Critically analyse (not just summarise!) Β· Identify gaps Β· Establish theoretical framework Β· Justify why current research is needed Β· Cite properly (APA/MLA/Chicago)
Research Design Β· Population & Sample Β· Data Collection instruments Β· Variables (Dependent/Independent) Β· Data Analysis Methods Β· Reliability & Validity Β· Limitations
Demographic Analysis Β· Analysis per objective Β· Tables & Figures (numbered, titled, sourced) Β· Statistical Tests (with calculated value, critical value, decision) Β· Interpretation in plain language after every table
Complete list of all sources cited. Consistent format throughout.
- Research Questionnaire
- Statistical tables used
- Raw data / Computer outputs
- Maps, Photographs
- Legal permissions obtained
| Element | Standard |
|---|---|
| Paper Size | A4 (210mm Γ 297mm) |
| Margins | Top/Bottom: 1 inch Β· Left: 1.5 inches (for binding) Β· Right: 1 inch |
| Font (Body) | Times New Roman 12pt or Arial 11pt |
| Font (Headings) | H1: 16β18pt Bold Β· H2: 14β16pt Bold Β· H3: 12β14pt Bold |
| Line Spacing | 1.5 lines for body Β· Single for tables, footnotes, references |
| Alignment | Justified (both left and right margins) |
| Page Numbering | Roman numerals (i, ii) for preliminary Β· Arabic (1, 2, 3) from Introduction |
| Tables & Figures | Table 4.1 Β· Title ABOVE table Β· Source BELOW Β· Caption below figure |
Internationally accepted structure for scientific research papers. Used in Harvard Business Review, Journal of Marketing Research, IJMS.
- Opening: 2β3 min β Greet, introduce, state title
- Problem Statement: 3β5 min β What & why
- Methodology: 5β8 min β How conducted
- Key Findings: 10β15 min β Most important results + visuals
- Conclusions & Reco: 5β8 min β What does it mean & what to do
- Q&A: 10β15 min β Be prepared!
- 6Γ6 Rule: Max 6 bullets per slide Β· Max 6 words per bullet
- Eye Contact: Look at audience, not screen
- Voice Modulation: Vary pitch, pace, volume
- Handling Questions: Listen β Repeat β Answer clearly
- Prep: Practice 3β4 times before delivery
| Chart Type | Best Used For | Example |
|---|---|---|
| π Bar Chart | Comparing categories (most common) | Sales comparison across 5 regions |
| π₯§ Pie Chart | Proportions & percentages of a whole | Market share: Tata, Hyundai, Maruti |
| π Line Graph | Trends over time | Monthly sales Jan to Dec |
| π Histogram | Frequency distribution of continuous data | Distribution of exam scores |
| π Scatter Plot | Relationship between two variables | Price vs demand, Ad spend vs sales |
| π¦ Box Plot | Spread and outliers in data | Salary range across departments |
GUI-based. Z/t/F/ΟΒ², Correlation, Regression, Factor Analysis, Cluster. Most used in social science.
AVERAGE, STDEV, CORREL, Pivot Tables, Data Analysis ToolPak. Perfect for MBA minor projects!
Requires coding. 15,000+ packages. Most advanced statistical capabilities. Popular in academia.
Pandas, NumPy, Matplotlib, Scikit-learn. Big data, ML. Most popular in AI research.
Used by ICICI, HDFC, Pharma companies. Handles millions of records. Risk analytics.
Forms auto-creates charts. Sheets has basic stats. Perfect for MBA minor research projects!
| Software | Cost | Ease | Power | Best For |
|---|---|---|---|---|
| SPSS | Paid | Easy (GUI) | High | Social research Β· MBA/PhD |
| Excel | Paid | Very Easy | Medium | Business analysis Β· MBA |
| R | Free | Difficult (code) | Very High | Academic research Β· PhD |
| Python | Free | Moderate | Very High | Big Data / ML Β· Tech |
| SAS | Very Expensive | Moderate | Very High | Banking / Pharma Β· Corporate |
| Google Sheets | Free | Very Easy | Low | Small surveys Β· Minor Project |
Complete research from problem to final report.
Conduct research once, sell to multiple clients who share the cost.
Surveys exclusively through digital platforms. Large online panels.
Large-scale official research for policy-making.
| β Common Mistake | β How to Avoid |
|---|---|
| Vague research problem | Be specific: WHO, WHAT, WHERE, WHEN. Not "Study of sales" but "Impact of Instagram ads on SME sales in Pune (2024)" |
| Too many objectives | Limit to 3β5. Each objective must have a corresponding analysis section. |
| Poor literature review | Don't just summarise β critically analyse. Identify contradictions & gaps. |
| Methodology not justified | Always explain WHY you chose a method. Why convenience? Why n=50? |
| Data without interpretation | After every table/test, write what it MEANS in plain language. |
| Missing citations | Every borrowed idea/stat must be cited. Use Zotero or Mendeley. |
| Overgeneralization | Don't claim 50-person sample findings apply to the entire world! |
| Findings = Conclusions | Findings = WHAT Β· Conclusions = SO WHAT Β· Recommendations = NOW WHAT |
| Informal language | No contractions (don't, can't), no slang, formal academic tone throughout. |
- Title page complete with all required information
- Declaration and certificate signed
- All objectives have corresponding analysis sections
- Every table has a number, title, and interpretation
- All statistical tests include calculated value, critical value & decision
- All sources cited in bibliography
- Questionnaire attached as appendix
- Consistent font, spacing, and page numbering throughout
- Abstract/executive summary written LAST, is accurate
- Word count is within required limits
Large sample, Ο known, nβ₯30
Small sample / Ο unknown, n<30
Mean Square Between Γ· Mean Square Within. 3+ groups.
E = (Row Total Γ Col Total) Γ· Grand Total
N = Population size Β· n = Sample size
Z=1.96 at 95% confidence Β· p=0.5 (worst case) Β· E=margin of error
- G.C. Beri: Define BEFORE you explain
- S.L. Gupta & H. Gupta: Always give Indian company examples
- Cooper & Schindler: Practical application & decision-making
- Naval Bajpai: Step-by-step processes
- Brayman & Bell: Research design & methodology rigor
P.R. Pote Patil College of Engineering & Management, Amravati
Ref: Brayman & Bell Β· G.C. Beri Β· Naval Bajpai Β· S.L. Gupta & H. Gupta Β· Donald Cooper & Pamela Schindler