CHAPTER 1: INTRODUCTION TO STATISTICS - LOGISTICS AND MARITIME STUDENTS

Vocabulary flashcards covering the fundamental concepts, data types, sampling methods, and graphical representations used in maritime and logistics statistics.

Statistics

The science of collecting, organising, presenting, analysing and interpreting numerical data for the purpose of decision-making.

Stages in Statistical Investigation

The four main stages: data collection, data presentation, data analysis, and interpretation.

Descriptive Statistics

A branch of statistics which summarises data using tables, charts and averages.

Inferential Statistics

A branch of statistics which uses sample data to draw conclusions about a population.

Population

The entire group under study, such as all vessels docking at a port within a year.

Sample

A subset selected from a population.

Parameter

A characteristic that describes a population.

Statistic

A characteristic that describes a sample.

Variable

Any measurable characteristic.

Qualitative Variables

Variables that represent qualities, such as vessel type.

Quantitative Variables

Variables that represent quantities, such as cargo weight, distance travelled, or fuel consumption.

Nominal Scale

A scale that classifies data without ranking.

Ordinal Scale

A scale that ranks data in order.

Interval Scale

A scale that measures differences but has no true zero.

Ratio Scale

A scale that has a true zero and allows full mathematical operations, used for most maritime data like time, distance, and weight.

Discrete Data

Countable values, such as the number of containers handled daily.

Continuous Data

Values that can take any value within a range, such as vessel turnaround time or fuel consumption.

Primary Data

Data collected directly through surveys, interviews or observation.

Secondary Data

Data from published reports and institutional databases, such as those from the International Maritime Organization or the World Bank.

Sampling

The process of selecting a representative subset from a population.

Probability Sampling

A sampling method that ensures every member of the population has a known and equal chance of selection.

Simple Random Sampling

A method where every member has an equal and independent chance of being selected.

Systematic Sampling

A method where every $k^{th}$ element is selected after choosing a random starting point.

Stratified Sampling

A method where the population is divided into homogeneous subgroups (strata) and samples are taken from each.

Cluster Sampling

A method where the population is divided into clusters, often geographically, and entire clusters are randomly selected.

Non-Probability Sampling

Sampling that does not provide equal selection chances, often used in qualitative or exploratory studies.

Convenience Sampling

A non-probability method involving the selection of easily accessible individuals.

Judgmental (Purposive) Sampling

A non-probability selection method based on researcher expertise.

Quota Sampling

A non-probability method involving the selection of a fixed number from each segment of the population.

Snowball Sampling

A non-probability method where existing participants refer additional participants.

Bar Chart

A visual representation of categorical or discrete data where bar height corresponds to frequency.

Histogram

A visual representation of continuous data grouped into intervals where bars touch.

Line Graph

A graphical tool that displays trends over time, such as cargo throughput or shipping demand.

Pie Chart

A chart showing proportional distribution of how a whole is divided among categories.

Ogive (Cumulative Frequency Curve)

A curve used to determine medians, quartiles and percentiles by showing how many observations fall below a particular value.

Skewness

The lack of symmetry in a distribution.

Symmetrical Distribution

A distribution where the $\text{mean}$, $\text{median}$ and $\text{mode}$ are equal.

Positively Skewed Distribution

A distribution with a long tail to the right where $\text{Mean} > \text{Median} > \text{Mode}$.

Negatively Skewed Distribution

A distribution with a long tail to the left where $\text{Mean} < \text{Median} < \text{Mode}$.