Understanding drama ratings

Korean TV ratings are calculated by research companies that install meters in a sample of households and record which channels they watch and for how long. Nielsen Korea is one of the most frequently cited sources. Because ratings are based on a sample, they can differ from the actual total number of viewers.

A household rating of 10%, the figure most news reports use, means roughly 10% of the TV-owning households in the survey sample watched the program. Individual ratings, which count people rather than households, are measured separately and give different numbers. Checking which basis an article uses helps you read ratings accurately.

Ratings reports often give both a nationwide figure, based on households across the country, and a metropolitan figure covering only Seoul, Gyeonggi and Incheon. The same program can score differently on each. When comparing dramas, make sure you compare numbers measured on the same basis, or the comparison will be misleading.

Terrestrial channels are available in almost every household and tend to post higher ratings, while cable and general programming channels usually record lower numbers. So the same figure can mean very different success depending on the channel. Some observers say the gap between channel types has narrowed compared with the past.

With smartphones, on-demand replays and streaming services, people watch in many more ways, so live TV ratings no longer capture a show's full popularity. That makes it hard to compare older and newer dramas by ratings alone. The industry now also looks at buzz rankings and replay data alongside traditional ratings.

A hwajeseong, or buzz index, measures how much a program is talked about by analyzing news articles, online posts, videos and social media reactions. Several organizations publish weekly rankings, but they cover different targets and use different indicators, so their rankings should not be compared directly. Check which organization an article's figures come from.

Weekend evening family dramas are often watched by the whole family, and their long runs build a loyal audience. As a result, terrestrial weekend dramas frequently post high ratings. Younger viewers, however, often watch in other ways, so ratings alone do not tell you how popular a drama is with every age group.

Dongsigandae 1wi means a program had higher ratings than other shows airing at the same time. It is a phrase often used in news and promotions, but the result can depend on which channels are compared and which ratings basis is used. It is a different concept from ranking first among all programs that day or week.

Ratings influence advertising sales and how broadcasters evaluate a show, so they matter in decisions about a drama. A strong response can lead to added episodes or talk of another season, while weak numbers can change scheduling. Recently, overseas sales and streaming performance are also considered alongside domestic ratings.

First-episode ratings show initial interest and get a lot of media coverage. However, many dramas grow steadily through word of mouth and see ratings climb sharply in later episodes. The final episode's rating or the peak rating often reflects a drama's overall trajectory better than the premiere alone, so it is worth watching the trend.

The TV ratings usually reported in the news focus on viewing during the broadcast slot, and streaming figures are tracked separately. However, some research firms also publish metrics that combine reruns and video-on-demand viewing, so what is included depends on the metric. Check which basis an article's numbers use before drawing conclusions about audience size.

Not necessarily. Some dramas had modest ratings in Korea but became huge hits overseas, and the reverse also happens. Viewing habits, broadcast channels and cultural tastes differ, so domestic ratings and international popularity do not always match. International popularity is better gauged through streaming rankings or global buzz.

When reading a ratings article, first check the research firm, whether the figure is nationwide or metropolitan, and whether it is a household or individual rating. The same program on the same day can show different numbers depending on the basis. It is best not to judge a drama's worth from a single number.

The KBS drama First Love from the 1990s is often cited as holding the all-time ratings record, with a peak reported in the 60% range. Back then, there were far fewer channels and ways to watch, so it is hard to compare with today's dramas. Check the research firm's records for exact figures.

Jogi jongyeong means ending a drama before its originally planned number of episodes. It can happen for various reasons, such as low ratings, production issues or scheduling changes. The opposite, adding episodes because a drama is very popular, is called yeonjang, or extension, and it is usually announced partway through the run.

TV ads in high-rated time slots reach more people, so ratings affect how advertising is sold. That is why broadcasters treat ratings as a key performance indicator. These days, advertisers often care more about whether a particular age group is watching than about the overall household figure, which changes how ratings are read.

No. Ratings only reflect live TV viewing, so they miss replays, streaming and international reactions. Many dramas with modest ratings are still loved for years or receive strong critical praise. Viewers who enjoy a drama should not feel that low numbers reduce its value, since ratings measure only one kind of audience.

In Korea, research firms such as Nielsen Korea and TNMS publish TV ratings. Nielsen Korea's figures are often cited in the press, but some outlets and programs use TNMS figures instead. Each company uses different samples and methods, so numbers for the same program can differ. Always check which source an article lists when you see a ratings figure.

Many dramas hit their peak rating in the last episode as viewers tune in to see how the story ends. People who joined midway through word of mouth also tend to watch the finale live. That is why articles about a drama's ending often highlight its final-episode rating as a measure of overall success.

Knowing about ratings helps you understand how a drama was received in Korea itself. Ratings come up constantly in Korean news and fan communities, so understanding the basics makes those conversations easier to follow. For a drama's popularity abroad, though, it is better to look at other indicators such as global streaming rankings.