An alternative hypothesis is a hypothesis that proposes a relationship between variables. This can include any hypothesis that predicts a positive correlation, a negative correlation, a non-directional correlation, or causation between variables. The only hypothesis that is not considered an alternative hypothesis is the null hypothesis, which predicts that there is no relationship between the independent and dependent variables.

Some examples of alternative hypotheses might include:

• If a researcher is studying the relationship between exercise and weight loss, their alternative hypothesis might be that there is a positive correlation between the two variables – that is, as exercise increases, weight loss also increases.
• If a researcher is studying the relationship between sleep and academic performance, their alternative hypothesis might be that there is a negative correlation between the two variables – that is, as sleep decreases, academic performance decreases.
• If a researcher is studying the relationship between diet and heart disease, their alternative hypothesis might be that there is a causal relationship between the two variables – that is, certain dietary factors cause heart disease.

Overall, an alternative hypothesis is any hypothesis that proposes a relationship between variables, as opposed to the null hypothesis, which predicts no relationship. More examples of alternative hypothesis include:

• Years of martial arts experience has a positive correlation with personal resilience.
• Coffee drinkers have higher average productivity than people who don’t drink coffee.
• Temperature influences the volume of alcohol.
• Rain causes mud puddles.
• There is a positive correlation between the price of silver and gold.
• Beeswax can be used to waterproof shoes.
• People feel happier on Fridays.
• People use the internet more on Mondays than any other day of the week.
• Social media use has a positive correlation with self-reported unhappiness.
• Smoking has a negative correlation with health.
• Income has a positive correlation with residential air quality.
• Room color influences mood.
• Temperature influences the strength of bamboo.
• Residential noise pollution has a positive correlation with self-reported stress levels.
• Low air quality has a negative correlation to health.
• Bacteria growth is correlated with air temperature.
• Fluid intelligence is positively correlated to career advancement and income.