This story was originally published on Nov. 21, 2018.

Calgary classrooms are becoming more and more crowded, as dozens of high-school courses brim with 40 students or more and the vast majority of elementary classes exceed Alberta guidelines, an analysis of provincial data shows.

Nearly 68 per cent of classes offered by the Calgary Board of Education (CBE) — across all grades — exceeded target levels in the 2017/18 school year. That's up from 47 per cent a decade earlier.

The increase comes even as the Alberta government has spent billions trying to shrink class sizes across the province.

How do your local schools stack up? Take a look at provincial class-size data in the interactive charts below

At the Calgary Catholic School District, the numbers are similar, with 63 per cent of classes exceeding the guidelines in the last academic year, up from 53 per cent a decade ago.

Janet Hawkins, a Calgary mom, says her daughter is struggling to learn at school because her Grade 3 class is overcrowded with 28 students. She had about 30 classmates in each of the previous two years, despite the fact that the guidelines call for a maximum of 17 students per class in kindergarten to Grade 3.

"With so many kids in the class, they get so little face time with the teachers," Hawkins said.

The mom said she and her husband hired tutors for both their daughters — their eldest is in Grade 6 — and spend hours each day going over workbooks to ensure they're getting the help they need.

"It's a huge amount of work for even just learning the basics," Hawkins said. "It's just not happening in the classroom."

A closer look at the data

The CBC News analysis, based on a massive swath of class-size data from Alberta Education, shows Calgary's two largest school authorities have among the highest proportion of overcrowded classrooms in the province.

The analysis isn't perfect, because blended classrooms that may have three grades in a single room are counted once. But it shows Calgary teachers are contending with greater workloads and, in many cases, have a dozen more students than what's recommended

So, how do Calgary classrooms stack up, exactly?

Below is an interactive chart including data for all the schools within both the CBE and CCSD. You can click or tap on the drop-down menu to look at data for each school.

(Can't see the chart? Click here for a version that should work on your mobile device.)

Another way to look at it is by geography.

Schools with large class sizes can be found throughout Calgary but they are especially common in suburban areas.

You can see for yourself in the map below. Again, it includes schools in both the CBE and CCSD.

Green dots indicate schools with 50 per cent or fewer classes exceeding the class-size targets. Yellow are those with 50 to 75 per cent exceeding the targets. And red indicates schools with more than 75 per cent of classes above the target levels.

(Can't see the map? Click here for a version that should work on your mobile device.)

School board officials say class sizes are only one factor they consider when weighing the quality of education, however.

They say the provincial data fails to account for additional staff in schools, such as educational assistants and speech language aides.

"It's about meeting the individual needs of those students and what works best with the resources that we have to make sure that we meet all of those needs," said CCSD board chair Cheryl Low.

"It's best reflected in the results.… We consistently see high academic performance in our district."

Where the guidelines come from

The provincial government adopted its class size guidelines from a 2003 report by Alberta's Commission on Learning.

Aside from calling for a maximum of 17 students in kindergarten to Grade 3, it also recommended class sizes of no more than 23 students in Grades 4 to 6, 25 students in junior high and 27 in high school.

The report's authors drew a link between smaller classes and better academic results, but they stressed that having engaged students and well-prepared teachers is also critical.

They based their guidelines on studies, such as international standardized test reports that tracked student scores against class sizes, though they noted the research wasn't perfect.

The province followed the commission's recommendation not to set legislated limits on class sizes, but to allow some flexibility. The goal was for school boards to meet the guidelines on average, which meant not every class would meet them.

Billions spent

To reach these goals, the government transferred more than $2.7 billion to school districts since 2004 to hire more teachers, according a report from the auditor general earlier this year.

Despite all this expense, fewer school boards met the guidelines last year than when the funding program started.

The report found the province hasn't had a plan to achieve its targets for more than a decade. It also criticized using class averages as the target, noting it "obscures" the number of classes that fail to meet the guidelines.

The interactive chart below shows how class sizes looked across all school authorities last year, compared to a decade ago.

(Can't see the map? Click here for a version that should work on your mobile device.)

The Calgary Board of Education said it spends all of the $51 million it receives each year from the class-size fund to hire teachers in kindergarten to Grade 3, given those students are learning critical skills, such as reading and writing.

Still, the CBE continues to fall short of the guidelines.

The provincial data shows 88 per cent of the school board's kindergarten-to-Grade 3 classes are too big. A dozen or so schools have classes in this age range with at least 27 students — 10 more than what's recommended.

"I believe that is primarily due to the fact that the costs of providing public education have exceeded the rate at which overall funding has flown into public education in Alberta," said Brad Grundy, the CBE's chief financial officer.

Education Minister David Eggen could not be reached for an interview. Instead, the province issued a written statement saying it's taken steps to address the problem, such as requiring school boards to show where they're spending the class size funding, a requirement that was scrapped about nine years ago.

'Class sizes have gotten worse'

The province has also built 31 new schools in Calgary since 2014, with eight more on the way.

"While we recognize there's clearly more to do, we're pleased that — on average — kids in Alberta continue to learn in reasonably small classrooms," the government said in its statement.

The average kindergarten-to-Grade 3 classroom had just over 20 students while all other grades had an average of fewer than 24 students, according to the statement.

(Can't see the map? Click here for a version that should work on your mobile device.)

The CBC News analysis shows, however, that looking at the total number of classes province-wide, 57 per cent of them fail to meet the guidelines. And about 81 per cent of kindergarten-to-Grade 3 classes fall short of the standard.

Barbara Silva, with Support our Students Alberta, said the numbers come as no surprise and show Alberta governments have long failed to address bulging classrooms.

"The daily lived realities of Alberta children in Alberta public schools has not changed, not just in four years, but in decades," Silva said.

"Class sizes have gotten worse."